1
0
Fork 0
python-docs-fr/howto/logging-cookbook.po

2009 lines
90 KiB
Plaintext
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# Copyright (C) 2001-2018, Python Software Foundation
# For licence information, see README file.
#
msgid ""
msgstr ""
"Project-Id-Version: Python 3\n"
"Report-Msgid-Bugs-To: \n"
"POT-Creation-Date: 2022-05-22 23:13+0200\n"
"PO-Revision-Date: 2022-04-30 16:34+0200\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
"Language-Team: FRENCH <traductions@lists.afpy.org>\n"
"Language: fr\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"X-Generator: Poedit 2.4.2\n"
#: howto/logging-cookbook.rst:5
msgid "Logging Cookbook"
msgstr "Recettes pour la journalisation"
#: howto/logging-cookbook.rst:0
msgid "Author"
msgstr "Auteur"
#: howto/logging-cookbook.rst:7
msgid "Vinay Sajip <vinay_sajip at red-dove dot com>"
msgstr "Vinay Sajip <vinay_sajip at red-dove dot com>"
#: howto/logging-cookbook.rst:9
msgid ""
"This page contains a number of recipes related to logging, which have been "
"found useful in the past."
msgstr ""
"Cette page contient des recettes relatives à la journalisation qui se sont "
"avérées utiles par le passé."
#: howto/logging-cookbook.rst:15
msgid "Using logging in multiple modules"
msgstr "Journalisation dans plusieurs modules"
#: howto/logging-cookbook.rst:17
msgid ""
"Multiple calls to ``logging.getLogger('someLogger')`` return a reference to "
"the same logger object. This is true not only within the same module, but "
"also across modules as long as it is in the same Python interpreter "
"process. It is true for references to the same object; additionally, "
"application code can define and configure a parent logger in one module and "
"create (but not configure) a child logger in a separate module, and all "
"logger calls to the child will pass up to the parent. Here is a main "
"module::"
msgstr ""
"Deux appels à ``logging.getLogger('unLogger')`` renvoient toujours une "
"référence vers le même objet de journalisation. C'est valable à l'intérieur "
"d'un module, mais aussi dans des modules différents pour autant que ce soit "
"le même processus de l'interpréteur Python. En plus, le code d'une "
"application peut définir et configurer une journalisation parente dans un "
"module et créer (mais pas configurer) une journalisation fille dans un "
"module séparé. Les appels à la journalisation fille passeront alors à la "
"journalisation parente. Voici un module principal ::"
#: howto/logging-cookbook.rst:55
msgid "Here is the auxiliary module::"
msgstr "Voici un module auxiliaire ::"
#: howto/logging-cookbook.rst:75
msgid "The output looks like this:"
msgstr "La sortie ressemble à ceci ::"
#: howto/logging-cookbook.rst:101
msgid "Logging from multiple threads"
msgstr "Journalisation avec des fils d'exécution multiples"
#: howto/logging-cookbook.rst:103
msgid ""
"Logging from multiple threads requires no special effort. The following "
"example shows logging from the main (initial) thread and another thread::"
msgstr ""
"La journalisation avec des fils d'exécution multiples ne requiert pas "
"d'effort particulier. L'exemple suivant montre comment journaliser depuis le "
"fil principal (c.-à-d. initial) et un autre fil ::"
#: howto/logging-cookbook.rst:132
msgid "When run, the script should print something like the following:"
msgstr "À l'exécution, le script doit afficher quelque chose comme ça ::"
#: howto/logging-cookbook.rst:154
msgid ""
"This shows the logging output interspersed as one might expect. This "
"approach works for more threads than shown here, of course."
msgstr ""
"Les entrées de journalisation sont entrelacées, comme on pouvait s'y "
"attendre. Cette approche fonctionne aussi avec plus de fils que dans "
"l'exemple, bien sûr."
#: howto/logging-cookbook.rst:158
msgid "Multiple handlers and formatters"
msgstr "Plusieurs gestionnaires et formateurs"
#: howto/logging-cookbook.rst:160
msgid ""
"Loggers are plain Python objects. The :meth:`~Logger.addHandler` method has "
"no minimum or maximum quota for the number of handlers you may add. "
"Sometimes it will be beneficial for an application to log all messages of "
"all severities to a text file while simultaneously logging errors or above "
"to the console. To set this up, simply configure the appropriate handlers. "
"The logging calls in the application code will remain unchanged. Here is a "
"slight modification to the previous simple module-based configuration "
"example::"
msgstr ""
"Les gestionnaires de journalisation sont des objets Python ordinaires. La "
"méthode :meth:`~Logger.addHandler` n'est pas limitée, en nombre minimum ou "
"maximum, en gestionnaires que vous pouvez ajouter. Parfois, il peut être "
"utile pour une application de journaliser tous les messages quels que soient "
"leurs niveaux vers un fichier texte, tout en journalisant les erreurs (et "
"plus grave) dans la console. Pour ce faire, configurez simplement les "
"gestionnaires de manière adéquate. Les appels de journalisation dans le code "
"de l'application resteront les mêmes. Voici une légère modification de "
"l'exemple précédent dans une configuration au niveau du module ::"
#: howto/logging-cookbook.rst:193
msgid ""
"Notice that the 'application' code does not care about multiple handlers. "
"All that changed was the addition and configuration of a new handler named "
"*fh*."
msgstr ""
"Notez que le code de « l'application » ignore la multiplicité des "
"gestionnaires. Les modifications consistent simplement en l'ajout et la "
"configuration d'un nouveau gestionnaire appelé *fh*."
#: howto/logging-cookbook.rst:196
msgid ""
"The ability to create new handlers with higher- or lower-severity filters "
"can be very helpful when writing and testing an application. Instead of "
"using many ``print`` statements for debugging, use ``logger.debug``: Unlike "
"the print statements, which you will have to delete or comment out later, "
"the logger.debug statements can remain intact in the source code and remain "
"dormant until you need them again. At that time, the only change that needs "
"to happen is to modify the severity level of the logger and/or handler to "
"debug."
msgstr ""
"La possibilité de créer de nouveaux gestionnaires avec des filtres sur un "
"niveau de gravité supérieur ou inférieur peut être très utile lors de "
"l'écriture ou du test d'une application. Au lieu d'utiliser de nombreuses "
"instructions ``print`` pour le débogage, utilisez ``logger.debug`` : "
"contrairement aux instructions ``print``, que vous devrez supprimer ou "
"commenter plus tard, les instructions ``logger.debug`` peuvent demeurer "
"telles quelles dans le code source et restent dormantes jusqu'à ce que vous "
"en ayez à nouveau besoin. À ce moment-là, il suffit de modifier le niveau de "
"gravité de la journalisation ou du gestionnaire pour déboguer."
#: howto/logging-cookbook.rst:207
msgid "Logging to multiple destinations"
msgstr "Journalisation vers plusieurs destinations"
#: howto/logging-cookbook.rst:209
msgid ""
"Let's say you want to log to console and file with different message formats "
"and in differing circumstances. Say you want to log messages with levels of "
"DEBUG and higher to file, and those messages at level INFO and higher to the "
"console. Let's also assume that the file should contain timestamps, but the "
"console messages should not. Here's how you can achieve this::"
msgstr ""
"Supposons que vous souhaitiez journaliser dans la console et dans un fichier "
"avec différents formats de messages et avec différents critères. Supposons "
"que vous souhaitiez consigner les messages de niveau DEBUG et supérieur dans "
"le fichier, et les messages de niveau INFO et supérieur dans la console. "
"Supposons également que le fichier doive contenir des horodatages, mais pas "
"les messages de la console. Voici comment y parvenir ::"
#: howto/logging-cookbook.rst:247
msgid "When you run this, on the console you will see"
msgstr "Quand vous le lancez, vous devez voir"
#: howto/logging-cookbook.rst:256
msgid "and in the file you will see something like"
msgstr "et, dans le fichier, vous devez trouver"
#: howto/logging-cookbook.rst:266
msgid ""
"As you can see, the DEBUG message only shows up in the file. The other "
"messages are sent to both destinations."
msgstr ""
"Comme vous pouvez le constater, le message DEBUG n'apparaît que dans le "
"fichier. Les autres messages sont envoyés vers les deux destinations."
#: howto/logging-cookbook.rst:269
msgid ""
"This example uses console and file handlers, but you can use any number and "
"combination of handlers you choose."
msgstr ""
"Cet exemple utilise la console et des gestionnaires de fichier, mais vous "
"pouvez utiliser et combiner autant de gestionnaires que de besoin."
#: howto/logging-cookbook.rst:274
msgid "Configuration server example"
msgstr "Exemple d'un serveur de configuration"
#: howto/logging-cookbook.rst:276
msgid "Here is an example of a module using the logging configuration server::"
msgstr ""
"Voici un exemple de module mettant en œuvre la configuration de la "
"journalisation *via* un serveur ::"
#: howto/logging-cookbook.rst:307
msgid ""
"And here is a script that takes a filename and sends that file to the "
"server, properly preceded with the binary-encoded length, as the new logging "
"configuration::"
msgstr ""
"Et voici un script qui, à partir d'un nom de fichier, commence par envoyer "
"la taille du fichier encodée en binaire (comme il se doit), puis envoie ce "
"fichier au serveur pour définir la nouvelle configuration de "
"journalisation ::"
#: howto/logging-cookbook.rst:330
msgid "Dealing with handlers that block"
msgstr "Utilisation de gestionnaires bloquants"
#: howto/logging-cookbook.rst:334
msgid ""
"Sometimes you have to get your logging handlers to do their work without "
"blocking the thread you're logging from. This is common in web applications, "
"though of course it also occurs in other scenarios."
msgstr ""
"Parfois, il est nécessaire que les gestionnaires de journalisation fassent "
"leur travail sans bloquer le fil d'exécution qui émet des événements. C'est "
"généralement le cas dans les applications Web, mais aussi bien sûr dans "
"d'autres scénarios."
#: howto/logging-cookbook.rst:338
msgid ""
"A common culprit which demonstrates sluggish behaviour is the :class:"
"`SMTPHandler`: sending emails can take a long time, for a number of reasons "
"outside the developer's control (for example, a poorly performing mail or "
"network infrastructure). But almost any network-based handler can block: "
"Even a :class:`SocketHandler` operation may do a DNS query under the hood "
"which is too slow (and this query can be deep in the socket library code, "
"below the Python layer, and outside your control)."
msgstr ""
"Un gestionnaire classiquement lent est le :class:`SMTPHandler` : l'envoi d'e-"
"mails peut prendre beaucoup de temps, pour un certain nombre de raisons "
"indépendantes du développeur (par exemple, une infrastructure de messagerie "
"ou de réseau peu performante). Mais n'importe quel autre gestionnaire "
"utilisant le réseau ou presque peut aussi s'avérer bloquant : même une "
"simple opération :class:`SocketHandler` peut faire une requête DNS implicite "
"et être ainsi très lente (cette requête peut être enfouie profondément dans "
"le code de la bibliothèque d'accès réseau, sous la couche Python, et hors de "
"votre contrôle)."
#: howto/logging-cookbook.rst:346
msgid ""
"One solution is to use a two-part approach. For the first part, attach only "
"a :class:`QueueHandler` to those loggers which are accessed from performance-"
"critical threads. They simply write to their queue, which can be sized to a "
"large enough capacity or initialized with no upper bound to their size. The "
"write to the queue will typically be accepted quickly, though you will "
"probably need to catch the :exc:`queue.Full` exception as a precaution in "
"your code. If you are a library developer who has performance-critical "
"threads in their code, be sure to document this (together with a suggestion "
"to attach only ``QueueHandlers`` to your loggers) for the benefit of other "
"developers who will use your code."
msgstr ""
"Une solution consiste à utiliser une approche en deux parties. Pour la "
"première partie, affectez un seul :class:`QueueHandler` à la journalisation "
"des fils d'exécution critiques pour les performances. Ils écrivent "
"simplement dans leur file d'attente, qui peut être dimensionnée à une "
"capacité suffisamment grande ou initialisée sans limite supérieure en "
"taille. L'écriture dans la file d'attente est généralement acceptée "
"rapidement, mais nous vous conseillons quand même de prévoir d'intercepter "
"l'exception :exc:`queue.Full` par précaution dans votre code. Si vous "
"développez une bibliothèque avec des fils d'exécution critiques pour les "
"performances, documentez-le bien (avec une suggestion de n'affecter que des "
"``QueueHandlers`` à votre journalisation) pour faciliter le travail des "
"développeurs qui utilisent votre code."
#: howto/logging-cookbook.rst:357
msgid ""
"The second part of the solution is :class:`QueueListener`, which has been "
"designed as the counterpart to :class:`QueueHandler`. A :class:"
"`QueueListener` is very simple: it's passed a queue and some handlers, and "
"it fires up an internal thread which listens to its queue for LogRecords "
"sent from ``QueueHandlers`` (or any other source of ``LogRecords``, for that "
"matter). The ``LogRecords`` are removed from the queue and passed to the "
"handlers for processing."
msgstr ""
"La deuxième partie de la solution est la classe :class:`QueueListener`, "
"conçue comme l'homologue de :class:`QueueHandler`. Un :class:`QueueListener` "
"est très simple : vous lui passez une file d'attente et des gestionnaires, "
"et il lance un fil d'exécution interne qui scrute la file d'attente pour "
"récupérer les événements envoyés par les ``QueueHandlers`` (ou toute autre "
"source de ``LogRecords``, d'ailleurs). Les ``LogRecords`` sont supprimés de "
"la file d'attente et transmis aux gestionnaires pour traitement."
#: howto/logging-cookbook.rst:365
msgid ""
"The advantage of having a separate :class:`QueueListener` class is that you "
"can use the same instance to service multiple ``QueueHandlers``. This is "
"more resource-friendly than, say, having threaded versions of the existing "
"handler classes, which would eat up one thread per handler for no particular "
"benefit."
msgstr ""
"L'avantage d'avoir une classe :class:`QueueListener` séparée est que vous "
"pouvez utiliser la même instance pour servir plusieurs ``QueueHandlers``. "
"Cela consomme moins de ressources que des instances de gestionnaires "
"réparties chacune dans un fil d'exécution séparé."
#: howto/logging-cookbook.rst:370
msgid "An example of using these two classes follows (imports omitted)::"
msgstr ""
"Voici un exemple d'utilisation de ces deux classes (les importations sont "
"omises) ::"
#: howto/logging-cookbook.rst:388
msgid "which, when run, will produce:"
msgstr "ce qui produit ceci à l'exécution :"
#: howto/logging-cookbook.rst:394
msgid ""
"Prior to Python 3.5, the :class:`QueueListener` always passed every message "
"received from the queue to every handler it was initialized with. (This was "
"because it was assumed that level filtering was all done on the other side, "
"where the queue is filled.) From 3.5 onwards, this behaviour can be changed "
"by passing a keyword argument ``respect_handler_level=True`` to the "
"listener's constructor. When this is done, the listener compares the level "
"of each message with the handler's level, and only passes a message to a "
"handler if it's appropriate to do so."
msgstr ""
"Avant Python 3.5, la classe :class:`QueueListener` passait chaque message "
"reçu de la file d'attente à chaque gestionnaire avec lequel l'instance avait "
"été initialisée (on supposait que le filtrage de niveau était entièrement "
"effectué de l'autre côté, au niveau de l'alimentation de la file d'attente). "
"Depuis Python 3.5, le comportement peut être modifié en passant l'argument "
"par mot-clé ``respect_handler_level=True`` au constructeur. Dans ce cas, la "
"``QueueListener`` compare le niveau de chaque message avec le niveau défini "
"dans chaque gestionnaire et ne transmet le message que si c'est opportun."
#: howto/logging-cookbook.rst:407
msgid "Sending and receiving logging events across a network"
msgstr "Envoi et réception d'événements de journalisation à travers le réseau"
#: howto/logging-cookbook.rst:409
msgid ""
"Let's say you want to send logging events across a network, and handle them "
"at the receiving end. A simple way of doing this is attaching a :class:"
"`SocketHandler` instance to the root logger at the sending end::"
msgstr ""
"Supposons que vous souhaitiez envoyer des événements de journalisation sur "
"un réseau et les traiter à la réception. Une façon simple de faire est "
"d'attacher une instance :class:`SocketHandler` à la journalisation racine de "
"l'émetteur ::"
#: howto/logging-cookbook.rst:437
msgid ""
"At the receiving end, you can set up a receiver using the :mod:"
"`socketserver` module. Here is a basic working example::"
msgstr ""
"Vous pouvez configurer le récepteur en utilisant le module :mod:"
"`socketserver`. Voici un exemple élémentaire ::"
#: howto/logging-cookbook.rst:525
msgid ""
"First run the server, and then the client. On the client side, nothing is "
"printed on the console; on the server side, you should see something like:"
msgstr ""
"Lancez d'abord le serveur, puis le client. Côté client, rien ne s'affiche "
"sur la console ; côté serveur, vous devez voir quelque chose comme ça :"
#: howto/logging-cookbook.rst:537
msgid ""
"Note that there are some security issues with pickle in some scenarios. If "
"these affect you, you can use an alternative serialization scheme by "
"overriding the :meth:`~handlers.SocketHandler.makePickle` method and "
"implementing your alternative there, as well as adapting the above script to "
"use your alternative serialization."
msgstr ""
"Notez que ``pickle`` introduit des problèmes de sécurité dans certains "
"scénarios. Si vous êtes concerné, vous pouvez utiliser une sérialisation "
"alternative en surchargeant la méthode :meth:`~handlers.SocketHandler."
"makePickle` par votre propre implémentation, ainsi qu'en adaptant le script "
"ci-dessus pour utiliser votre sérialisation."
#: howto/logging-cookbook.rst:545
msgid "Running a logging socket listener in production"
msgstr ""
"Journalisation en production à l'aide d'un connecteur en écoute sur le réseau"
#: howto/logging-cookbook.rst:547
msgid ""
"To run a logging listener in production, you may need to use a process-"
"management tool such as `Supervisor <http://supervisord.org/>`_. `Here "
"<https://gist.github.com/vsajip/4b227eeec43817465ca835ca66f75e2b>`_ is a "
"Gist which provides the bare-bones files to run the above functionality "
"using Supervisor: you will need to change the `/path/to/` parts in the Gist "
"to reflect the actual paths you want to use."
msgstr ""
"Pour de la journalisation en production *via* un connecteur réseau en "
"écoute, il est probable que vous ayez besoin d'utiliser un outil de "
"surveillance tel que `Supervisor <http://supervisord.org/>`_. Vous trouverez "
"dans ce `Gist <https://gist.github.com/"
"vsajip/4b227eeec43817465ca835ca66f75e2b>`_ des gabarits pour assurer cette "
"fonction avec *Supervisor* : vous aurez besoin de modifier les parties `/"
"path/to/` du *Gist* pour refléter les chemins réels que vous utilisez."
#: howto/logging-cookbook.rst:558
msgid "Adding contextual information to your logging output"
msgstr "Ajout d'informations contextuelles dans la journalisation"
# #no-qa
#: howto/logging-cookbook.rst:560
msgid ""
"Sometimes you want logging output to contain contextual information in "
"addition to the parameters passed to the logging call. For example, in a "
"networked application, it may be desirable to log client-specific "
"information in the log (e.g. remote client's username, or IP address). "
"Although you could use the *extra* parameter to achieve this, it's not "
"always convenient to pass the information in this way. While it might be "
"tempting to create :class:`Logger` instances on a per-connection basis, this "
"is not a good idea because these instances are not garbage collected. While "
"this is not a problem in practice, when the number of :class:`Logger` "
"instances is dependent on the level of granularity you want to use in "
"logging an application, it could be hard to manage if the number of :class:"
"`Logger` instances becomes effectively unbounded."
msgstr ""
"Dans certains cas, vous pouvez souhaiter que la journalisation contienne des "
"informations contextuelles en plus des paramètres transmis à l'appel de "
"journalisation. Par exemple, dans une application réseau, il peut être "
"souhaitable de consigner des informations spécifiques au client dans le "
"journal (par exemple, le nom d'utilisateur ou l'adresse IP du client "
"distant). Bien que vous puissiez utiliser le paramètre *extra* pour y "
"parvenir, il n'est pas toujours pratique de transmettre les informations de "
"cette manière. Il peut être aussi tentant de créer des instances :class:"
"`Logger` connexion par connexion, mais ce n'est pas une bonne idée car ces "
"instances :class:`Logger` ne sont pas éliminées par le ramasse-miettes. Même "
"si ce point n'est pas problématique en soi si la journalisation est "
"configurée avec plusieurs niveaux de granularité, cela peut devenir "
"difficile de gérer un nombre potentiellement illimité d'instances de :class:"
"`Logger`."
#: howto/logging-cookbook.rst:575
msgid "Using LoggerAdapters to impart contextual information"
msgstr ""
"Utilisation d'adaptateurs de journalisation pour transmettre des "
"informations contextuelles"
#: howto/logging-cookbook.rst:577
msgid ""
"An easy way in which you can pass contextual information to be output along "
"with logging event information is to use the :class:`LoggerAdapter` class. "
"This class is designed to look like a :class:`Logger`, so that you can call :"
"meth:`debug`, :meth:`info`, :meth:`warning`, :meth:`error`, :meth:"
"`exception`, :meth:`critical` and :meth:`log`. These methods have the same "
"signatures as their counterparts in :class:`Logger`, so you can use the two "
"types of instances interchangeably."
msgstr ""
"Un moyen simple de transmettre des informations contextuelles accompagnant "
"les informations de journalisation consiste à utiliser la classe :class:"
"`LoggerAdapter`. Cette classe est conçue pour ressembler à un :class:"
"`Logger`, de sorte que vous pouvez appeler :meth:`debug`, :meth:`info`, :"
"meth:`warning`, :meth:`error`, :meth:`exception`, :meth:`critical` et :meth:"
"`log`. Ces méthodes ont les mêmes signatures que leurs homologues dans :"
"class:`Logger`, vous pouvez donc utiliser les deux types d'instances de "
"manière interchangeable."
#: howto/logging-cookbook.rst:585
msgid ""
"When you create an instance of :class:`LoggerAdapter`, you pass it a :class:"
"`Logger` instance and a dict-like object which contains your contextual "
"information. When you call one of the logging methods on an instance of :"
"class:`LoggerAdapter`, it delegates the call to the underlying instance of :"
"class:`Logger` passed to its constructor, and arranges to pass the "
"contextual information in the delegated call. Here's a snippet from the code "
"of :class:`LoggerAdapter`::"
msgstr ""
"Lorsque vous créez une instance de :class:`LoggerAdapter`, vous lui "
"transmettez une instance de :class:`Logger` et un objet dictionnaire qui "
"contient vos informations contextuelles. Lorsque vous appelez l'une des "
"méthodes de journalisation sur une instance de :class:`LoggerAdapter`, elle "
"délègue l'appel à l'instance sous-jacente de :class:`Logger` transmise à son "
"constructeur et s'arrange pour intégrer les informations contextuelles dans "
"l'appel délégué. Voici un extrait du code de :class:`LoggerAdapter` ::"
#: howto/logging-cookbook.rst:601
msgid ""
"The :meth:`~LoggerAdapter.process` method of :class:`LoggerAdapter` is where "
"the contextual information is added to the logging output. It's passed the "
"message and keyword arguments of the logging call, and it passes back "
"(potentially) modified versions of these to use in the call to the "
"underlying logger. The default implementation of this method leaves the "
"message alone, but inserts an 'extra' key in the keyword argument whose "
"value is the dict-like object passed to the constructor. Of course, if you "
"had passed an 'extra' keyword argument in the call to the adapter, it will "
"be silently overwritten."
msgstr ""
"Les informations contextuelles sont ajoutées dans la méthode :meth:"
"`~LoggerAdapter.process` de :class:`LoggerAdapter`. On lui passe le message "
"et les arguments par mot-clé de l'appel de journalisation, et elle en "
"renvoie des versions (potentiellement) modifiées à utiliser pour la "
"journalisation sous-jacente. L'implémentation par défaut de cette méthode "
"laisse le message seul, mais insère une clé ``extra`` dans l'argument par "
"mot-clé dont la valeur est l'objet dictionnaire passé au constructeur. Bien "
"sûr, si vous avez passé un argument par mot-clé ``extra`` dans l'appel à "
"l'adaptateur, il est écrasé silencieusement."
#: howto/logging-cookbook.rst:610
msgid ""
"The advantage of using 'extra' is that the values in the dict-like object "
"are merged into the :class:`LogRecord` instance's __dict__, allowing you to "
"use customized strings with your :class:`Formatter` instances which know "
"about the keys of the dict-like object. If you need a different method, e.g. "
"if you want to prepend or append the contextual information to the message "
"string, you just need to subclass :class:`LoggerAdapter` and override :meth:"
"`~LoggerAdapter.process` to do what you need. Here is a simple example::"
msgstr ""
"L'avantage d'utiliser ``extra`` est que les valeurs de l'objet dictionnaire "
"sont fusionnées dans le ``__dict__`` de l'instance :class:`LogRecord`, ce "
"qui vous permet d'utiliser des chaînes personnalisées avec vos instances :"
"class:`Formatter` qui connaissent les clés de l'objet dictionnaire. Si vous "
"avez besoin d'une méthode différente, par exemple si vous souhaitez ajouter "
"des informations contextuelles avant ou après la chaîne de message, il vous "
"suffit de surcharger :class:`LoggerAdapter` et de remplacer :meth:"
"`~LoggerAdapter.process` pour faire ce dont vous avez besoin. Voici un "
"exemple simple ::"
#: howto/logging-cookbook.rst:626
msgid "which you can use like this::"
msgstr "que vous pouvez utiliser comme ceci ::"
#: howto/logging-cookbook.rst:631
msgid ""
"Then any events that you log to the adapter will have the value of "
"``some_conn_id`` prepended to the log messages."
msgstr ""
"Ainsi, tout événement journalisé aura la valeur de ``some_conn_id`` insérée "
"en début de message de journalisation."
#: howto/logging-cookbook.rst:635
msgid "Using objects other than dicts to pass contextual information"
msgstr ""
"Utilisation d'objets autres que les dictionnaires pour passer des "
"informations contextuelles"
#: howto/logging-cookbook.rst:637
msgid ""
"You don't need to pass an actual dict to a :class:`LoggerAdapter` - you "
"could pass an instance of a class which implements ``__getitem__`` and "
"``__iter__`` so that it looks like a dict to logging. This would be useful "
"if you want to generate values dynamically (whereas the values in a dict "
"would be constant)."
msgstr ""
"Il n'est pas obligatoire de passer un dictionnaire réel à un :class:"
"`LoggerAdapter`, vous pouvez passer une instance d'une classe qui implémente "
"``__getitem__`` et ``__iter__`` pour qu'il ressemble à un dictionnaire du "
"point de vue de la journalisation. C'est utile si vous souhaitez générer des "
"valeurs de manière dynamique (alors que les valeurs d'un dictionnaire "
"seraient constantes)."
#: howto/logging-cookbook.rst:646
msgid "Using Filters to impart contextual information"
msgstr "Utilisation de filtres pour transmettre des informations contextuelles"
#: howto/logging-cookbook.rst:648
msgid ""
"You can also add contextual information to log output using a user-defined :"
"class:`Filter`. ``Filter`` instances are allowed to modify the "
"``LogRecords`` passed to them, including adding additional attributes which "
"can then be output using a suitable format string, or if needed a custom :"
"class:`Formatter`."
msgstr ""
"Un :class:`Filter` défini par l'utilisateur peut aussi ajouter des "
"informations contextuelles à la journalisation. Les instances de ``Filter`` "
"sont autorisées à modifier les ``LogRecords`` qui leur sont transmis, y "
"compris par l'ajout d'attributs supplémentaires qui peuvent ensuite être "
"intégrés à la journalisation en utilisant une chaîne de formatage appropriée "
"ou, si nécessaire, un :class:`Formatter` personnalisé."
#: howto/logging-cookbook.rst:653
msgid ""
"For example in a web application, the request being processed (or at least, "
"the interesting parts of it) can be stored in a threadlocal (:class:"
"`threading.local`) variable, and then accessed from a ``Filter`` to add, "
"say, information from the request - say, the remote IP address and remote "
"user's username - to the ``LogRecord``, using the attribute names 'ip' and "
"'user' as in the ``LoggerAdapter`` example above. In that case, the same "
"format string can be used to get similar output to that shown above. Here's "
"an example script::"
msgstr ""
"Par exemple, dans une application Web, la requête en cours de traitement (ou "
"du moins ce qu'elle contient d'intéressant) peut être stockée dans une "
"variable locale au fil d'exécution (:class:`threading.local`), puis utilisée "
"dans un ``Filter`` pour ajouter, par exemple, des informations relatives à "
"la requête (par exemple, l'adresse IP distante et le nom de l'utilisateur) "
"au ``LogRecord``, en utilisant les noms d'attribut ``ip`` et ``user`` comme "
"dans l'exemple ``LoggerAdapter`` ci-dessus. Dans ce cas, la même chaîne de "
"formatage peut être utilisée pour obtenir une sortie similaire à celle "
"indiquée ci-dessus. Voici un exemple de script ::"
#: howto/logging-cookbook.rst:699
msgid "which, when run, produces something like:"
msgstr "qui, à l'exécution, produit quelque chose comme ça ::"
#: howto/logging-cookbook.rst:720
msgid "Logging to a single file from multiple processes"
msgstr "Journalisation vers un fichier unique à partir de plusieurs processus"
#: howto/logging-cookbook.rst:722
msgid ""
"Although logging is thread-safe, and logging to a single file from multiple "
"threads in a single process *is* supported, logging to a single file from "
"*multiple processes* is *not* supported, because there is no standard way to "
"serialize access to a single file across multiple processes in Python. If "
"you need to log to a single file from multiple processes, one way of doing "
"this is to have all the processes log to a :class:`~handlers.SocketHandler`, "
"and have a separate process which implements a socket server which reads "
"from the socket and logs to file. (If you prefer, you can dedicate one "
"thread in one of the existing processes to perform this function.) :ref:"
"`This section <network-logging>` documents this approach in more detail and "
"includes a working socket receiver which can be used as a starting point for "
"you to adapt in your own applications."
msgstr ""
"La journalisation est fiable avec les programmes à fils d'exécution "
"multiples (thread-safe) : rien n'empêche plusieurs fils d'exécution de "
"journaliser dans le même fichier, du moment que ces fils d'exécution font "
"partie du même processus. En revanche, il n'existe aucun moyen standard de "
"sérialiser l'accès à un seul fichier sur plusieurs processus en Python. Si "
"vous avez besoin de vous connecter à un seul fichier à partir de plusieurs "
"processus, une façon de le faire est de faire en sorte que tous les "
"processus se connectent à un :class:`~handlers.SocketHandler`, et d'avoir un "
"processus séparé qui implémente un serveur qui lit à partir de ce connecteur "
"et écrit les journaux dans le fichier (si vous préférez, vous pouvez dédier "
"un fil d'exécution dans l'un des processus existants pour exécuter cette "
"tâche). :ref:`Cette section <network-logging>` documente cette approche plus "
"en détail et inclut un connecteur en écoute réseau fonctionnel qui peut être "
"utilisé comme point de départ pour l'adapter à vos propres applications."
#: howto/logging-cookbook.rst:735
msgid ""
"You could also write your own handler which uses the :class:"
"`~multiprocessing.Lock` class from the :mod:`multiprocessing` module to "
"serialize access to the file from your processes. The existing :class:"
"`FileHandler` and subclasses do not make use of :mod:`multiprocessing` at "
"present, though they may do so in the future. Note that at present, the :mod:"
"`multiprocessing` module does not provide working lock functionality on all "
"platforms (see https://bugs.python.org/issue3770)."
msgstr ""
"Vous pouvez également écrire votre propre gestionnaire en utilisant la "
"classe :class:`~multiprocessing.Lock` du module :mod:`multiprocessing` pour "
"sérialiser l'accès au fichier depuis vos processus. Les actuels :class:"
"`FileHandler` et sous-classes n'utilisent pas :mod:`multiprocessing` pour le "
"moment, même s'ils pourraient le faire à l'avenir. Notez qu'à l'heure "
"actuelle, le module :mod:`multiprocessing` ne fournit pas un verrouillage "
"fonctionnel pour toutes les plates-formes (voir https://bugs.python.org/"
"issue3770)."
#: howto/logging-cookbook.rst:745
msgid ""
"Alternatively, you can use a ``Queue`` and a :class:`QueueHandler` to send "
"all logging events to one of the processes in your multi-process "
"application. The following example script demonstrates how you can do this; "
"in the example a separate listener process listens for events sent by other "
"processes and logs them according to its own logging configuration. Although "
"the example only demonstrates one way of doing it (for example, you may want "
"to use a listener thread rather than a separate listener process -- the "
"implementation would be analogous) it does allow for completely different "
"logging configurations for the listener and the other processes in your "
"application, and can be used as the basis for code meeting your own specific "
"requirements::"
msgstr ""
"Autrement, vous pouvez utiliser une ``Queue`` et un :class:`QueueHandler` "
"pour envoyer tous les événements de journalisation à l'un des processus de "
"votre application multi-processus. L'exemple de script suivant montre "
"comment procéder ; dans l'exemple, un processus d'écoute distinct écoute les "
"événements envoyés par les autres processus et les journalise en fonction de "
"sa propre configuration de journalisation. Bien que l'exemple ne montre "
"qu'une seule façon de faire (par exemple, vous pouvez utiliser un fil "
"d'exécution d'écoute plutôt qu'un processus d'écoute séparé "
"l'implémentation serait analogue), il permet des configurations de "
"journalisation complètement différentes pour celui qui écoute ainsi que pour "
"les autres processus de votre application, et peut être utilisé comme base "
"pour répondre à vos propres exigences ::"
#: howto/logging-cookbook.rst:861
msgid ""
"A variant of the above script keeps the logging in the main process, in a "
"separate thread::"
msgstr ""
"Une variante du script ci-dessus conserve la journalisation dans le "
"processus principal, dans un fil séparé ::"
#: howto/logging-cookbook.rst:956
msgid ""
"This variant shows how you can e.g. apply configuration for particular "
"loggers - e.g. the ``foo`` logger has a special handler which stores all "
"events in the ``foo`` subsystem in a file ``mplog-foo.log``. This will be "
"used by the logging machinery in the main process (even though the logging "
"events are generated in the worker processes) to direct the messages to the "
"appropriate destinations."
msgstr ""
"Cette variante montre comment appliquer la configuration pour des "
"enregistreurs particuliers - par exemple l'enregistreur ``foo`` a un "
"gestionnaire spécial qui stocke tous les événements du sous-système ``foo`` "
"dans un fichier ``mplog-foo.log``. C'est utilisé par le mécanisme de "
"journalisation dans le processus principal (même si les événements de "
"journalisation sont générés dans les processus de travail) pour diriger les "
"messages vers les destinations appropriées."
#: howto/logging-cookbook.rst:963
msgid "Using concurrent.futures.ProcessPoolExecutor"
msgstr "Utilisation de concurrent.futures.ProcessPoolExecutor"
#: howto/logging-cookbook.rst:965
msgid ""
"If you want to use :class:`concurrent.futures.ProcessPoolExecutor` to start "
"your worker processes, you need to create the queue slightly differently. "
"Instead of"
msgstr ""
"Si vous souhaitez utiliser :class:`concurrent.futures.ProcessPoolExecutor` "
"pour démarrer vos processus de travail, vous devez créer la file d'attente "
"légèrement différemment. À la place de"
#: howto/logging-cookbook.rst:973
msgid "you should use"
msgstr "vous devez écrire"
#: howto/logging-cookbook.rst:979
msgid "and you can then replace the worker creation from this::"
msgstr ""
"et vous pouvez alors remplacer la création du processus de travail telle "
"que ::"
#: howto/logging-cookbook.rst:990
msgid "to this (remembering to first import :mod:`concurrent.futures`)::"
msgstr ""
"par celle-ci (souvenez-vous d'importer au préalable :mod:`concurrent."
"futures`) ::"
#: howto/logging-cookbook.rst:997
msgid "Deploying Web applications using Gunicorn and uWSGI"
msgstr "Déploiement d'applications Web avec *Gunicorn* et *uWSGI*"
#: howto/logging-cookbook.rst:999
msgid ""
"When deploying Web applications using `Gunicorn <https://gunicorn.org/>`_ or "
"`uWSGI <https://uwsgi-docs.readthedocs.io/en/latest/>`_ (or similar), "
"multiple worker processes are created to handle client requests. In such "
"environments, avoid creating file-based handlers directly in your web "
"application. Instead, use a :class:`SocketHandler` to log from the web "
"application to a listener in a separate process. This can be set up using a "
"process management tool such as Supervisor - see `Running a logging socket "
"listener in production`_ for more details."
msgstr ""
"Lors du déploiement d'applications Web qui utilisent `Gunicorn <https://"
"gunicorn.org/>`_ ou `uWSGI <https://uwsgi-docs.readthedocs.io/en/latest/>`_ "
"(ou équivalent), plusieurs processus de travail sont créés pour traiter les "
"requêtes des clients. Dans de tels environnements, évitez de créer des "
"gestionnaires à fichiers directement dans votre application Web. Au lieu de "
"cela, utilisez un :class:`SocketHandler` pour journaliser depuis "
"l'application Web vers gestionnaire réseau à l'écoute dans un processus "
"séparé. Cela peut être configuré à l'aide d'un outil de gestion de processus "
"tel que *Supervisor* (voir `Journalisation en production à l'aide d'un "
"connecteur en écoute sur le réseau`_ pour plus de détails)."
#: howto/logging-cookbook.rst:1009
msgid "Using file rotation"
msgstr "Utilisation du roulement de fichiers"
#: howto/logging-cookbook.rst:1014
msgid ""
"Sometimes you want to let a log file grow to a certain size, then open a new "
"file and log to that. You may want to keep a certain number of these files, "
"and when that many files have been created, rotate the files so that the "
"number of files and the size of the files both remain bounded. For this "
"usage pattern, the logging package provides a :class:`~handlers."
"RotatingFileHandler`::"
msgstr ""
"Parfois, vous souhaitez laisser un fichier de journalisation grossir jusqu'à "
"une certaine taille, puis ouvrir un nouveau fichier et vous y enregistrer "
"les nouveaux événements. Vous souhaitez peut-être conserver un certain "
"nombre de ces fichiers et, lorsque ce nombre de fichiers aura été créé, "
"faire rouler les fichiers afin que le nombre de fichiers et la taille des "
"fichiers restent tous deux limités. Pour ce cas d'usage, :class:`~handlers."
"RotatingFileHandler` est inclus dans le paquet de journalisation ::"
#: howto/logging-cookbook.rst:1046
msgid ""
"The result should be 6 separate files, each with part of the log history for "
"the application:"
msgstr ""
"Vous devez obtenir 6 fichiers séparés, chacun contenant une partie de "
"l'historique de journalisation de l'application :"
#: howto/logging-cookbook.rst:1058
msgid ""
"The most current file is always :file:`logging_rotatingfile_example.out`, "
"and each time it reaches the size limit it is renamed with the suffix "
"``.1``. Each of the existing backup files is renamed to increment the suffix "
"(``.1`` becomes ``.2``, etc.) and the ``.6`` file is erased."
msgstr ""
"Le fichier de journalisation actuel est toujours :file:"
"`logging_rotatingfile_example.out`, et chaque fois qu'il atteint la taille "
"limite, il est renommé avec le suffixe ``.1``. Chacun des fichiers de "
"sauvegarde existants est renommé pour incrémenter le suffixe (``.1`` devient "
"``.2``, etc.) et le fichier ``.6`` est effacé."
#: howto/logging-cookbook.rst:1063
msgid ""
"Obviously this example sets the log length much too small as an extreme "
"example. You would want to set *maxBytes* to an appropriate value."
msgstr ""
"De toute évidence, la longueur du journal définie dans cet exemple est "
"beaucoup trop petite. À vous de définir *maxBytes* à une valeur appropriée."
#: howto/logging-cookbook.rst:1069
msgid "Use of alternative formatting styles"
msgstr "Utilisation d'autres styles de formatage"
#: howto/logging-cookbook.rst:1071
msgid ""
"When logging was added to the Python standard library, the only way of "
"formatting messages with variable content was to use the %-formatting "
"method. Since then, Python has gained two new formatting approaches: :class:"
"`string.Template` (added in Python 2.4) and :meth:`str.format` (added in "
"Python 2.6)."
msgstr ""
"Lorsque la journalisation a été ajoutée à la bibliothèque standard Python, "
"la seule façon de formater les messages avec un contenu variable était "
"d'utiliser la méthode de formatage avec « % ». Depuis, Python s'est enrichi "
"de deux nouvelles méthode de formatage : :class:`string.Template` (ajouté "
"dans Python 2.4) et :meth:`str.format` (ajouté dans Python 2.6)."
#: howto/logging-cookbook.rst:1077
msgid ""
"Logging (as of 3.2) provides improved support for these two additional "
"formatting styles. The :class:`Formatter` class been enhanced to take an "
"additional, optional keyword parameter named ``style``. This defaults to "
"``'%'``, but other possible values are ``'{'`` and ``'$'``, which correspond "
"to the other two formatting styles. Backwards compatibility is maintained by "
"default (as you would expect), but by explicitly specifying a style "
"parameter, you get the ability to specify format strings which work with :"
"meth:`str.format` or :class:`string.Template`. Here's an example console "
"session to show the possibilities:"
msgstr ""
"La journalisation (à partir de la version 3.2) offre une meilleure prise en "
"charge de ces deux styles de formatage supplémentaires. La classe :class:"
"`Formatter` a été améliorée pour accepter un paramètre par mot-clé "
"facultatif supplémentaire nommé ``style``. La valeur par défaut est ``'%'``, "
"les autres valeurs possibles étant ``'{'`` et ``'$'``, qui correspondent aux "
"deux autres styles de formatage. La rétrocompatibilité est maintenue par "
"défaut (comme vous vous en doutez) mais, en spécifiant explicitement un "
"paramètre de style, vous avez la possibilité de spécifier des chaînes de "
"format qui fonctionnent avec :meth:`str.format` ou :class:`string.Template`. "
"Voici un exemple de session interactive en console pour montrer les "
"possibilités :"
#: howto/logging-cookbook.rst:1111
msgid ""
"Note that the formatting of logging messages for final output to logs is "
"completely independent of how an individual logging message is constructed. "
"That can still use %-formatting, as shown here::"
msgstr ""
"Notez que le formatage des messages de journalisation est, au final, "
"complètement indépendant de la façon dont un message de journalisation "
"individuel est construit. Vous pouvez toujours utiliser formatage *via* "
"« % », comme ici ::"
#: howto/logging-cookbook.rst:1119
msgid ""
"Logging calls (``logger.debug()``, ``logger.info()`` etc.) only take "
"positional parameters for the actual logging message itself, with keyword "
"parameters used only for determining options for how to handle the actual "
"logging call (e.g. the ``exc_info`` keyword parameter to indicate that "
"traceback information should be logged, or the ``extra`` keyword parameter "
"to indicate additional contextual information to be added to the log). So "
"you cannot directly make logging calls using :meth:`str.format` or :class:"
"`string.Template` syntax, because internally the logging package uses %-"
"formatting to merge the format string and the variable arguments. There "
"would be no changing this while preserving backward compatibility, since all "
"logging calls which are out there in existing code will be using %-format "
"strings."
msgstr ""
"Les appels de journalisation (``logger.debug()``, ``logger.info()`` etc.) ne "
"prennent que des paramètres positionnels pour le message de journalisation "
"lui-même, les paramètres par mots-clés étant utilisés uniquement pour "
"déterminer comment gérer le message réel (par exemple, le paramètre par mot-"
"clé ``exc_info`` indique que les informations de trace doivent être "
"enregistrées, ou le paramètre par mot-clé ``extra`` indique des informations "
"contextuelles supplémentaires à ajouter au journal). Vous ne pouvez donc pas "
"inclure dans les appels de journalisation à l'aide de la syntaxe :meth:`str."
"format` ou :class:`string.Template`, car le paquet de journalisation utilise "
"le formatage via « % » en interne pour fusionner la chaîne de format et les "
"arguments de variables. Il n'est pas possible de changer ça tout en "
"préservant la rétrocompatibilité puisque tous les appels de journalisation "
"dans le code pré-existant utilisent des chaînes au format « % »."
#: howto/logging-cookbook.rst:1132
msgid ""
"There is, however, a way that you can use {}- and $- formatting to construct "
"your individual log messages. Recall that for a message you can use an "
"arbitrary object as a message format string, and that the logging package "
"will call ``str()`` on that object to get the actual format string. Consider "
"the following two classes::"
msgstr ""
"Il existe cependant un moyen d'utiliser le formatage *via* « {} » et « $ » "
"pour vos messages de journalisation. Rappelez-vous que, pour un message, "
"vous pouvez utiliser un objet arbitraire comme chaîne de format de message, "
"et que le package de journalisation appelle ``str()`` sur cet objet pour "
"fabriquer la chaîne finale. Considérez les deux classes suivantes ::"
#: howto/logging-cookbook.rst:1156
msgid ""
"Either of these can be used in place of a format string, to allow {}- or $-"
"formatting to be used to build the actual \"message\" part which appears in "
"the formatted log output in place of \"%(message)s\" or \"{message}\" or "
"\"$message\". It's a little unwieldy to use the class names whenever you "
"want to log something, but it's quite palatable if you use an alias such as "
"__ (double underscore --- not to be confused with _, the single underscore "
"used as a synonym/alias for :func:`gettext.gettext` or its brethren)."
msgstr ""
"L'une ou l'autre peut être utilisée à la place d'une chaîne de format "
"\"%(message)s\" ou \"{message}\" ou \"$message\", afin de mettre en forme "
"*via* « { } » ou « $ » la partie « message réel » qui apparaît dans la "
"sortie de journal formatée. Il est un peu lourd d'utiliser les noms de "
"classe chaque fois que vous voulez journaliser quelque chose, mais ça "
"devient acceptable si vous utilisez un alias tel que __ (double trait de "
"soulignement — à ne pas confondre avec _, le trait de soulignement unique "
"utilisé comme alias pour :func:`gettext.gettext` ou ses homologues)."
#: howto/logging-cookbook.rst:1164
msgid ""
"The above classes are not included in Python, though they're easy enough to "
"copy and paste into your own code. They can be used as follows (assuming "
"that they're declared in a module called ``wherever``):"
msgstr ""
"Les classes ci-dessus ne sont pas incluses dans Python, bien qu'elles soient "
"assez faciles à copier et coller dans votre propre code. Elles peuvent être "
"utilisées comme suit (en supposant qu'elles soient déclarées dans un module "
"appelé ``wherever``) :"
#: howto/logging-cookbook.rst:1186
msgid ""
"While the above examples use ``print()`` to show how the formatting works, "
"you would of course use ``logger.debug()`` or similar to actually log using "
"this approach."
msgstr ""
"Alors que les exemples ci-dessus utilisent ``print()`` pour montrer comment "
"fonctionne le formatage, utilisez bien sûr ``logger.debug()`` ou similaire "
"pour journaliser avec cette approche."
#: howto/logging-cookbook.rst:1190
msgid ""
"One thing to note is that you pay no significant performance penalty with "
"this approach: the actual formatting happens not when you make the logging "
"call, but when (and if) the logged message is actually about to be output to "
"a log by a handler. So the only slightly unusual thing which might trip you "
"up is that the parentheses go around the format string and the arguments, "
"not just the format string. That's because the __ notation is just syntax "
"sugar for a constructor call to one of the XXXMessage classes."
msgstr ""
"Une chose à noter est qu'il n'y a pas de perte de performance significative "
"avec cette approche : le formatage réel ne se produit pas lorsque vous "
"effectuez l'appel de journalisation, mais lorsque (et si) le message "
"journalisé est réellement sur le point d'être écrit dans un journal par un "
"gestionnaire. Ainsi, la seule chose légèrement inhabituelle qui pourrait "
"vous perturber est que les parenthèses entourent la chaîne de format et les "
"arguments, pas seulement la chaîne de format. C'est parce que la notation __ "
"n'est que du sucre syntaxique pour un appel de constructeur à l'une des "
"classes `XXXMessage`."
#: howto/logging-cookbook.rst:1198
msgid ""
"If you prefer, you can use a :class:`LoggerAdapter` to achieve a similar "
"effect to the above, as in the following example::"
msgstr ""
"Si vous préférez, vous pouvez utiliser un :class:`LoggerAdapter` pour "
"obtenir un effet similaire à ce qui précède, comme dans l'exemple suivant ::"
#: howto/logging-cookbook.rst:1229
msgid ""
"The above script should log the message ``Hello, world!`` when run with "
"Python 3.2 or later."
msgstr ""
"Le script ci-dessus journalise le message ``Hello, world!`` quand il est "
"lancé avec Python 3.2 ou ultérieur."
#: howto/logging-cookbook.rst:1238
msgid "Customizing ``LogRecord``"
msgstr ""
#: howto/logging-cookbook.rst:1240
msgid ""
"Every logging event is represented by a :class:`LogRecord` instance. When an "
"event is logged and not filtered out by a logger's level, a :class:"
"`LogRecord` is created, populated with information about the event and then "
"passed to the handlers for that logger (and its ancestors, up to and "
"including the logger where further propagation up the hierarchy is "
"disabled). Before Python 3.2, there were only two places where this creation "
"was done:"
msgstr ""
#: howto/logging-cookbook.rst:1247
msgid ""
":meth:`Logger.makeRecord`, which is called in the normal process of logging "
"an event. This invoked :class:`LogRecord` directly to create an instance."
msgstr ""
#: howto/logging-cookbook.rst:1250
msgid ""
":func:`makeLogRecord`, which is called with a dictionary containing "
"attributes to be added to the LogRecord. This is typically invoked when a "
"suitable dictionary has been received over the network (e.g. in pickle form "
"via a :class:`~handlers.SocketHandler`, or in JSON form via an :class:"
"`~handlers.HTTPHandler`)."
msgstr ""
#: howto/logging-cookbook.rst:1256
msgid ""
"This has usually meant that if you need to do anything special with a :class:"
"`LogRecord`, you've had to do one of the following."
msgstr ""
#: howto/logging-cookbook.rst:1259
msgid ""
"Create your own :class:`Logger` subclass, which overrides :meth:`Logger."
"makeRecord`, and set it using :func:`~logging.setLoggerClass` before any "
"loggers that you care about are instantiated."
msgstr ""
#: howto/logging-cookbook.rst:1262
msgid ""
"Add a :class:`Filter` to a logger or handler, which does the necessary "
"special manipulation you need when its :meth:`~Filter.filter` method is "
"called."
msgstr ""
#: howto/logging-cookbook.rst:1266
msgid ""
"The first approach would be a little unwieldy in the scenario where (say) "
"several different libraries wanted to do different things. Each would "
"attempt to set its own :class:`Logger` subclass, and the one which did this "
"last would win."
msgstr ""
#: howto/logging-cookbook.rst:1271
msgid ""
"The second approach works reasonably well for many cases, but does not allow "
"you to e.g. use a specialized subclass of :class:`LogRecord`. Library "
"developers can set a suitable filter on their loggers, but they would have "
"to remember to do this every time they introduced a new logger (which they "
"would do simply by adding new packages or modules and doing ::"
msgstr ""
#: howto/logging-cookbook.rst:1279
msgid ""
"at module level). It's probably one too many things to think about. "
"Developers could also add the filter to a :class:`~logging.NullHandler` "
"attached to their top-level logger, but this would not be invoked if an "
"application developer attached a handler to a lower-level library logger --- "
"so output from that handler would not reflect the intentions of the library "
"developer."
msgstr ""
#: howto/logging-cookbook.rst:1285
msgid ""
"In Python 3.2 and later, :class:`~logging.LogRecord` creation is done "
"through a factory, which you can specify. The factory is just a callable you "
"can set with :func:`~logging.setLogRecordFactory`, and interrogate with :"
"func:`~logging.getLogRecordFactory`. The factory is invoked with the same "
"signature as the :class:`~logging.LogRecord` constructor, as :class:"
"`LogRecord` is the default setting for the factory."
msgstr ""
#: howto/logging-cookbook.rst:1292
msgid ""
"This approach allows a custom factory to control all aspects of LogRecord "
"creation. For example, you could return a subclass, or just add some "
"additional attributes to the record once created, using a pattern similar to "
"this::"
msgstr ""
#: howto/logging-cookbook.rst:1305
msgid ""
"This pattern allows different libraries to chain factories together, and as "
"long as they don't overwrite each other's attributes or unintentionally "
"overwrite the attributes provided as standard, there should be no surprises. "
"However, it should be borne in mind that each link in the chain adds run-"
"time overhead to all logging operations, and the technique should only be "
"used when the use of a :class:`Filter` does not provide the desired result."
msgstr ""
#: howto/logging-cookbook.rst:1316
msgid "Subclassing QueueHandler - a ZeroMQ example"
msgstr ""
#: howto/logging-cookbook.rst:1318
msgid ""
"You can use a :class:`QueueHandler` subclass to send messages to other kinds "
"of queues, for example a ZeroMQ 'publish' socket. In the example below,the "
"socket is created separately and passed to the handler (as its 'queue')::"
msgstr ""
#: howto/logging-cookbook.rst:1337
msgid ""
"Of course there are other ways of organizing this, for example passing in "
"the data needed by the handler to create the socket::"
msgstr ""
#: howto/logging-cookbook.rst:1355
msgid "Subclassing QueueListener - a ZeroMQ example"
msgstr ""
#: howto/logging-cookbook.rst:1357
msgid ""
"You can also subclass :class:`QueueListener` to get messages from other "
"kinds of queues, for example a ZeroMQ 'subscribe' socket. Here's an example::"
msgstr ""
#: howto/logging-cookbook.rst:1376
msgid "Module :mod:`logging`"
msgstr "Module :mod:`logging`"
#: howto/logging-cookbook.rst:1376
msgid "API reference for the logging module."
msgstr "Référence d'API pour le module de journalisation."
#: howto/logging-cookbook.rst:1379
msgid "Module :mod:`logging.config`"
msgstr "Module :mod:`logging.config`"
#: howto/logging-cookbook.rst:1379
msgid "Configuration API for the logging module."
msgstr "API de configuration pour le module de journalisation."
#: howto/logging-cookbook.rst:1382
msgid "Module :mod:`logging.handlers`"
msgstr "Module :mod:`logging.handlers`"
#: howto/logging-cookbook.rst:1382
msgid "Useful handlers included with the logging module."
msgstr "Gestionnaires utiles inclus avec le module de journalisation."
#: howto/logging-cookbook.rst:1384
msgid ":ref:`A basic logging tutorial <logging-basic-tutorial>`"
msgstr ""
#: howto/logging-cookbook.rst:1386
msgid ":ref:`A more advanced logging tutorial <logging-advanced-tutorial>`"
msgstr ""
#: howto/logging-cookbook.rst:1390
msgid "An example dictionary-based configuration"
msgstr ""
#: howto/logging-cookbook.rst:1392
msgid ""
"Below is an example of a logging configuration dictionary - it's taken from "
"the `documentation on the Django project <https://docs.djangoproject.com/en/"
"stable/topics/logging/#configuring-logging>`_. This dictionary is passed to :"
"func:`~config.dictConfig` to put the configuration into effect::"
msgstr ""
#: howto/logging-cookbook.rst:1448
msgid ""
"For more information about this configuration, you can see the `relevant "
"section <https://docs.djangoproject.com/en/stable/topics/logging/"
"#configuring-logging>`_ of the Django documentation."
msgstr ""
#: howto/logging-cookbook.rst:1455
msgid "Using a rotator and namer to customize log rotation processing"
msgstr ""
#: howto/logging-cookbook.rst:1457
msgid ""
"An example of how you can define a namer and rotator is given in the "
"following snippet, which shows zlib-based compression of the log file::"
msgstr ""
#: howto/logging-cookbook.rst:1475
msgid ""
"These are not \"true\" .gz files, as they are bare compressed data, with no "
"\"container\" such as youd find in an actual gzip file. This snippet is "
"just for illustration purposes."
msgstr ""
#: howto/logging-cookbook.rst:1480
msgid "A more elaborate multiprocessing example"
msgstr ""
#: howto/logging-cookbook.rst:1482
msgid ""
"The following working example shows how logging can be used with "
"multiprocessing using configuration files. The configurations are fairly "
"simple, but serve to illustrate how more complex ones could be implemented "
"in a real multiprocessing scenario."
msgstr ""
#: howto/logging-cookbook.rst:1487
msgid ""
"In the example, the main process spawns a listener process and some worker "
"processes. Each of the main process, the listener and the workers have three "
"separate configurations (the workers all share the same configuration). We "
"can see logging in the main process, how the workers log to a QueueHandler "
"and how the listener implements a QueueListener and a more complex logging "
"configuration, and arranges to dispatch events received via the queue to the "
"handlers specified in the configuration. Note that these configurations are "
"purely illustrative, but you should be able to adapt this example to your "
"own scenario."
msgstr ""
#: howto/logging-cookbook.rst:1497
msgid ""
"Here's the script - the docstrings and the comments hopefully explain how it "
"works::"
msgstr ""
#: howto/logging-cookbook.rst:1709
msgid "Inserting a BOM into messages sent to a SysLogHandler"
msgstr ""
#: howto/logging-cookbook.rst:1711
msgid ""
":rfc:`5424` requires that a Unicode message be sent to a syslog daemon as a "
"set of bytes which have the following structure: an optional pure-ASCII "
"component, followed by a UTF-8 Byte Order Mark (BOM), followed by Unicode "
"encoded using UTF-8. (See the :rfc:`relevant section of the specification "
"<5424#section-6>`.)"
msgstr ""
#: howto/logging-cookbook.rst:1717
msgid ""
"In Python 3.1, code was added to :class:`~logging.handlers.SysLogHandler` to "
"insert a BOM into the message, but unfortunately, it was implemented "
"incorrectly, with the BOM appearing at the beginning of the message and "
"hence not allowing any pure-ASCII component to appear before it."
msgstr ""
#: howto/logging-cookbook.rst:1723
msgid ""
"As this behaviour is broken, the incorrect BOM insertion code is being "
"removed from Python 3.2.4 and later. However, it is not being replaced, and "
"if you want to produce :rfc:`5424`-compliant messages which include a BOM, "
"an optional pure-ASCII sequence before it and arbitrary Unicode after it, "
"encoded using UTF-8, then you need to do the following:"
msgstr ""
#: howto/logging-cookbook.rst:1729
msgid ""
"Attach a :class:`~logging.Formatter` instance to your :class:`~logging."
"handlers.SysLogHandler` instance, with a format string such as::"
msgstr ""
#: howto/logging-cookbook.rst:1735
msgid ""
"The Unicode code point U+FEFF, when encoded using UTF-8, will be encoded as "
"a UTF-8 BOM -- the byte-string ``b'\\xef\\xbb\\xbf'``."
msgstr ""
#: howto/logging-cookbook.rst:1738
msgid ""
"Replace the ASCII section with whatever placeholders you like, but make sure "
"that the data that appears in there after substitution is always ASCII (that "
"way, it will remain unchanged after UTF-8 encoding)."
msgstr ""
#: howto/logging-cookbook.rst:1742
msgid ""
"Replace the Unicode section with whatever placeholders you like; if the data "
"which appears there after substitution contains characters outside the ASCII "
"range, that's fine -- it will be encoded using UTF-8."
msgstr ""
#: howto/logging-cookbook.rst:1746
msgid ""
"The formatted message *will* be encoded using UTF-8 encoding by "
"``SysLogHandler``. If you follow the above rules, you should be able to "
"produce :rfc:`5424`-compliant messages. If you don't, logging may not "
"complain, but your messages will not be RFC 5424-compliant, and your syslog "
"daemon may complain."
msgstr ""
#: howto/logging-cookbook.rst:1753
msgid "Implementing structured logging"
msgstr ""
#: howto/logging-cookbook.rst:1755
msgid ""
"Although most logging messages are intended for reading by humans, and thus "
"not readily machine-parseable, there might be circumstances where you want "
"to output messages in a structured format which *is* capable of being parsed "
"by a program (without needing complex regular expressions to parse the log "
"message). This is straightforward to achieve using the logging package. "
"There are a number of ways in which this could be achieved, but the "
"following is a simple approach which uses JSON to serialise the event in a "
"machine-parseable manner::"
msgstr ""
#: howto/logging-cookbook.rst:1779
msgid "If the above script is run, it prints:"
msgstr ""
#: howto/logging-cookbook.rst:1785 howto/logging-cookbook.rst:1827
msgid ""
"Note that the order of items might be different according to the version of "
"Python used."
msgstr ""
#: howto/logging-cookbook.rst:1788
msgid ""
"If you need more specialised processing, you can use a custom JSON encoder, "
"as in the following complete example::"
msgstr ""
#: howto/logging-cookbook.rst:1821
msgid "When the above script is run, it prints:"
msgstr ""
#: howto/logging-cookbook.rst:1836
msgid "Customizing handlers with :func:`dictConfig`"
msgstr ""
#: howto/logging-cookbook.rst:1838
msgid ""
"There are times when you want to customize logging handlers in particular "
"ways, and if you use :func:`dictConfig` you may be able to do this without "
"subclassing. As an example, consider that you may want to set the ownership "
"of a log file. On POSIX, this is easily done using :func:`shutil.chown`, but "
"the file handlers in the stdlib don't offer built-in support. You can "
"customize handler creation using a plain function such as::"
msgstr ""
#: howto/logging-cookbook.rst:1852
msgid ""
"You can then specify, in a logging configuration passed to :func:"
"`dictConfig`, that a logging handler be created by calling this function::"
msgstr ""
#: howto/logging-cookbook.rst:1885
msgid ""
"In this example I am setting the ownership using the ``pulse`` user and "
"group, just for the purposes of illustration. Putting it together into a "
"working script, ``chowntest.py``::"
msgstr ""
#: howto/logging-cookbook.rst:1932
msgid "To run this, you will probably need to run as ``root``:"
msgstr ""
#: howto/logging-cookbook.rst:1942
msgid ""
"Note that this example uses Python 3.3 because that's where :func:`shutil."
"chown` makes an appearance. This approach should work with any Python "
"version that supports :func:`dictConfig` - namely, Python 2.7, 3.2 or later. "
"With pre-3.3 versions, you would need to implement the actual ownership "
"change using e.g. :func:`os.chown`."
msgstr ""
#: howto/logging-cookbook.rst:1948
msgid ""
"In practice, the handler-creating function may be in a utility module "
"somewhere in your project. Instead of the line in the configuration::"
msgstr ""
#: howto/logging-cookbook.rst:1953
msgid "you could use e.g.::"
msgstr ""
#: howto/logging-cookbook.rst:1957
msgid ""
"where ``project.util`` can be replaced with the actual name of the package "
"where the function resides. In the above working script, using ``'ext://"
"__main__.owned_file_handler'`` should work. Here, the actual callable is "
"resolved by :func:`dictConfig` from the ``ext://`` specification."
msgstr ""
#: howto/logging-cookbook.rst:1962
msgid ""
"This example hopefully also points the way to how you could implement other "
"types of file change - e.g. setting specific POSIX permission bits - in the "
"same way, using :func:`os.chmod`."
msgstr ""
#: howto/logging-cookbook.rst:1966
msgid ""
"Of course, the approach could also be extended to types of handler other "
"than a :class:`~logging.FileHandler` - for example, one of the rotating file "
"handlers, or a different type of handler altogether."
msgstr ""
#: howto/logging-cookbook.rst:1976
msgid "Using particular formatting styles throughout your application"
msgstr ""
#: howto/logging-cookbook.rst:1978
msgid ""
"In Python 3.2, the :class:`~logging.Formatter` gained a ``style`` keyword "
"parameter which, while defaulting to ``%`` for backward compatibility, "
"allowed the specification of ``{`` or ``$`` to support the formatting "
"approaches supported by :meth:`str.format` and :class:`string.Template`. "
"Note that this governs the formatting of logging messages for final output "
"to logs, and is completely orthogonal to how an individual logging message "
"is constructed."
msgstr ""
#: howto/logging-cookbook.rst:1985
msgid ""
"Logging calls (:meth:`~Logger.debug`, :meth:`~Logger.info` etc.) only take "
"positional parameters for the actual logging message itself, with keyword "
"parameters used only for determining options for how to handle the logging "
"call (e.g. the ``exc_info`` keyword parameter to indicate that traceback "
"information should be logged, or the ``extra`` keyword parameter to indicate "
"additional contextual information to be added to the log). So you cannot "
"directly make logging calls using :meth:`str.format` or :class:`string."
"Template` syntax, because internally the logging package uses %-formatting "
"to merge the format string and the variable arguments. There would no "
"changing this while preserving backward compatibility, since all logging "
"calls which are out there in existing code will be using %-format strings."
msgstr ""
#: howto/logging-cookbook.rst:1997
msgid ""
"There have been suggestions to associate format styles with specific "
"loggers, but that approach also runs into backward compatibility problems "
"because any existing code could be using a given logger name and using %-"
"formatting."
msgstr ""
#: howto/logging-cookbook.rst:2001
msgid ""
"For logging to work interoperably between any third-party libraries and your "
"code, decisions about formatting need to be made at the level of the "
"individual logging call. This opens up a couple of ways in which alternative "
"formatting styles can be accommodated."
msgstr ""
#: howto/logging-cookbook.rst:2008
msgid "Using LogRecord factories"
msgstr ""
#: howto/logging-cookbook.rst:2010
msgid ""
"In Python 3.2, along with the :class:`~logging.Formatter` changes mentioned "
"above, the logging package gained the ability to allow users to set their "
"own :class:`LogRecord` subclasses, using the :func:`setLogRecordFactory` "
"function. You can use this to set your own subclass of :class:`LogRecord`, "
"which does the Right Thing by overriding the :meth:`~LogRecord.getMessage` "
"method. The base class implementation of this method is where the ``msg % "
"args`` formatting happens, and where you can substitute your alternate "
"formatting; however, you should be careful to support all formatting styles "
"and allow %-formatting as the default, to ensure interoperability with other "
"code. Care should also be taken to call ``str(self.msg)``, just as the base "
"implementation does."
msgstr ""
#: howto/logging-cookbook.rst:2021
msgid ""
"Refer to the reference documentation on :func:`setLogRecordFactory` and :"
"class:`LogRecord` for more information."
msgstr ""
#: howto/logging-cookbook.rst:2026
msgid "Using custom message objects"
msgstr ""
#: howto/logging-cookbook.rst:2028
msgid ""
"There is another, perhaps simpler way that you can use {}- and $- formatting "
"to construct your individual log messages. You may recall (from :ref:"
"`arbitrary-object-messages`) that when logging you can use an arbitrary "
"object as a message format string, and that the logging package will call :"
"func:`str` on that object to get the actual format string. Consider the "
"following two classes::"
msgstr ""
#: howto/logging-cookbook.rst:2053
msgid ""
"Either of these can be used in place of a format string, to allow {}- or $-"
"formatting to be used to build the actual \"message\" part which appears in "
"the formatted log output in place of “%(message)s” or “{message}” or "
"“$message”. If you find it a little unwieldy to use the class names whenever "
"you want to log something, you can make it more palatable if you use an "
"alias such as ``M`` or ``_`` for the message (or perhaps ``__``, if you are "
"using ``_`` for localization)."
msgstr ""
#: howto/logging-cookbook.rst:2061
msgid ""
"Examples of this approach are given below. Firstly, formatting with :meth:"
"`str.format`::"
msgstr ""
#: howto/logging-cookbook.rst:2075
msgid "Secondly, formatting with :class:`string.Template`::"
msgstr ""
#: howto/logging-cookbook.rst:2082
msgid ""
"One thing to note is that you pay no significant performance penalty with "
"this approach: the actual formatting happens not when you make the logging "
"call, but when (and if) the logged message is actually about to be output to "
"a log by a handler. So the only slightly unusual thing which might trip you "
"up is that the parentheses go around the format string and the arguments, "
"not just the format string. Thats because the __ notation is just syntax "
"sugar for a constructor call to one of the ``XXXMessage`` classes shown "
"above."
msgstr ""
#: howto/logging-cookbook.rst:2096
msgid "Configuring filters with :func:`dictConfig`"
msgstr ""
#: howto/logging-cookbook.rst:2098
msgid ""
"You *can* configure filters using :func:`~logging.config.dictConfig`, though "
"it might not be obvious at first glance how to do it (hence this recipe). "
"Since :class:`~logging.Filter` is the only filter class included in the "
"standard library, and it is unlikely to cater to many requirements (it's "
"only there as a base class), you will typically need to define your own :"
"class:`~logging.Filter` subclass with an overridden :meth:`~logging.Filter."
"filter` method. To do this, specify the ``()`` key in the configuration "
"dictionary for the filter, specifying a callable which will be used to "
"create the filter (a class is the most obvious, but you can provide any "
"callable which returns a :class:`~logging.Filter` instance). Here is a "
"complete example::"
msgstr ""
#: howto/logging-cookbook.rst:2151
msgid ""
"This example shows how you can pass configuration data to the callable which "
"constructs the instance, in the form of keyword parameters. When run, the "
"above script will print:"
msgstr ""
#: howto/logging-cookbook.rst:2159
msgid "which shows that the filter is working as configured."
msgstr ""
#: howto/logging-cookbook.rst:2161
msgid "A couple of extra points to note:"
msgstr ""
#: howto/logging-cookbook.rst:2163
msgid ""
"If you can't refer to the callable directly in the configuration (e.g. if it "
"lives in a different module, and you can't import it directly where the "
"configuration dictionary is), you can use the form ``ext://...`` as "
"described in :ref:`logging-config-dict-externalobj`. For example, you could "
"have used the text ``'ext://__main__.MyFilter'`` instead of ``MyFilter`` in "
"the above example."
msgstr ""
#: howto/logging-cookbook.rst:2170
msgid ""
"As well as for filters, this technique can also be used to configure custom "
"handlers and formatters. See :ref:`logging-config-dict-userdef` for more "
"information on how logging supports using user-defined objects in its "
"configuration, and see the other cookbook recipe :ref:`custom-handlers` "
"above."
msgstr ""
#: howto/logging-cookbook.rst:2179
msgid "Customized exception formatting"
msgstr ""
#: howto/logging-cookbook.rst:2181
msgid ""
"There might be times when you want to do customized exception formatting - "
"for argument's sake, let's say you want exactly one line per logged event, "
"even when exception information is present. You can do this with a custom "
"formatter class, as shown in the following example::"
msgstr ""
#: howto/logging-cookbook.rst:2222
msgid "When run, this produces a file with exactly two lines:"
msgstr ""
#: howto/logging-cookbook.rst:2229
msgid ""
"While the above treatment is simplistic, it points the way to how exception "
"information can be formatted to your liking. The :mod:`traceback` module may "
"be helpful for more specialized needs."
msgstr ""
#: howto/logging-cookbook.rst:2236
msgid "Speaking logging messages"
msgstr ""
#: howto/logging-cookbook.rst:2238
msgid ""
"There might be situations when it is desirable to have logging messages "
"rendered in an audible rather than a visible format. This is easy to do if "
"you have text-to-speech (TTS) functionality available in your system, even "
"if it doesn't have a Python binding. Most TTS systems have a command line "
"program you can run, and this can be invoked from a handler using :mod:"
"`subprocess`. It's assumed here that TTS command line programs won't expect "
"to interact with users or take a long time to complete, and that the "
"frequency of logged messages will be not so high as to swamp the user with "
"messages, and that it's acceptable to have the messages spoken one at a time "
"rather than concurrently, The example implementation below waits for one "
"message to be spoken before the next is processed, and this might cause "
"other handlers to be kept waiting. Here is a short example showing the "
"approach, which assumes that the ``espeak`` TTS package is available::"
msgstr ""
#: howto/logging-cookbook.rst:2280
msgid ""
"When run, this script should say \"Hello\" and then \"Goodbye\" in a female "
"voice."
msgstr ""
#: howto/logging-cookbook.rst:2282
msgid ""
"The above approach can, of course, be adapted to other TTS systems and even "
"other systems altogether which can process messages via external programs "
"run from a command line."
msgstr ""
#: howto/logging-cookbook.rst:2290
msgid "Buffering logging messages and outputting them conditionally"
msgstr ""
#: howto/logging-cookbook.rst:2292
msgid ""
"There might be situations where you want to log messages in a temporary area "
"and only output them if a certain condition occurs. For example, you may "
"want to start logging debug events in a function, and if the function "
"completes without errors, you don't want to clutter the log with the "
"collected debug information, but if there is an error, you want all the "
"debug information to be output as well as the error."
msgstr ""
#: howto/logging-cookbook.rst:2299
msgid ""
"Here is an example which shows how you could do this using a decorator for "
"your functions where you want logging to behave this way. It makes use of "
"the :class:`logging.handlers.MemoryHandler`, which allows buffering of "
"logged events until some condition occurs, at which point the buffered "
"events are ``flushed`` - passed to another handler (the ``target`` handler) "
"for processing. By default, the ``MemoryHandler`` flushed when its buffer "
"gets filled up or an event whose level is greater than or equal to a "
"specified threshold is seen. You can use this recipe with a more specialised "
"subclass of ``MemoryHandler`` if you want custom flushing behavior."
msgstr ""
#: howto/logging-cookbook.rst:2309
msgid ""
"The example script has a simple function, ``foo``, which just cycles through "
"all the logging levels, writing to ``sys.stderr`` to say what level it's "
"about to log at, and then actually logging a message at that level. You can "
"pass a parameter to ``foo`` which, if true, will log at ERROR and CRITICAL "
"levels - otherwise, it only logs at DEBUG, INFO and WARNING levels."
msgstr ""
#: howto/logging-cookbook.rst:2315
msgid ""
"The script just arranges to decorate ``foo`` with a decorator which will do "
"the conditional logging that's required. The decorator takes a logger as a "
"parameter and attaches a memory handler for the duration of the call to the "
"decorated function. The decorator can be additionally parameterised using a "
"target handler, a level at which flushing should occur, and a capacity for "
"the buffer (number of records buffered). These default to a :class:`~logging."
"StreamHandler` which writes to ``sys.stderr``, ``logging.ERROR`` and ``100`` "
"respectively."
msgstr ""
#: howto/logging-cookbook.rst:2323
msgid "Here's the script::"
msgstr ""
#: howto/logging-cookbook.rst:2386
msgid "When this script is run, the following output should be observed:"
msgstr ""
#: howto/logging-cookbook.rst:2416
msgid ""
"As you can see, actual logging output only occurs when an event is logged "
"whose severity is ERROR or greater, but in that case, any previous events at "
"lower severities are also logged."
msgstr ""
#: howto/logging-cookbook.rst:2420
msgid "You can of course use the conventional means of decoration::"
msgstr ""
#: howto/logging-cookbook.rst:2430
msgid "Formatting times using UTC (GMT) via configuration"
msgstr ""
#: howto/logging-cookbook.rst:2432
msgid ""
"Sometimes you want to format times using UTC, which can be done using a "
"class such as `UTCFormatter`, shown below::"
msgstr ""
#: howto/logging-cookbook.rst:2441
msgid ""
"and you can then use the ``UTCFormatter`` in your code instead of :class:"
"`~logging.Formatter`. If you want to do that via configuration, you can use "
"the :func:`~logging.config.dictConfig` API with an approach illustrated by "
"the following complete example::"
msgstr ""
#: howto/logging-cookbook.rst:2484
msgid "When this script is run, it should print something like:"
msgstr ""
#: howto/logging-cookbook.rst:2491
msgid ""
"showing how the time is formatted both as local time and UTC, one for each "
"handler."
msgstr ""
#: howto/logging-cookbook.rst:2498
msgid "Using a context manager for selective logging"
msgstr ""
#: howto/logging-cookbook.rst:2500
msgid ""
"There are times when it would be useful to temporarily change the logging "
"configuration and revert it back after doing something. For this, a context "
"manager is the most obvious way of saving and restoring the logging context. "
"Here is a simple example of such a context manager, which allows you to "
"optionally change the logging level and add a logging handler purely in the "
"scope of the context manager::"
msgstr ""
#: howto/logging-cookbook.rst:2533
msgid ""
"If you specify a level value, the logger's level is set to that value in the "
"scope of the with block covered by the context manager. If you specify a "
"handler, it is added to the logger on entry to the block and removed on exit "
"from the block. You can also ask the manager to close the handler for you on "
"block exit - you could do this if you don't need the handler any more."
msgstr ""
#: howto/logging-cookbook.rst:2539
msgid ""
"To illustrate how it works, we can add the following block of code to the "
"above::"
msgstr ""
#: howto/logging-cookbook.rst:2557
msgid ""
"We initially set the logger's level to ``INFO``, so message #1 appears and "
"message #2 doesn't. We then change the level to ``DEBUG`` temporarily in the "
"following ``with`` block, and so message #3 appears. After the block exits, "
"the logger's level is restored to ``INFO`` and so message #4 doesn't appear. "
"In the next ``with`` block, we set the level to ``DEBUG`` again but also add "
"a handler writing to ``sys.stdout``. Thus, message #5 appears twice on the "
"console (once via ``stderr`` and once via ``stdout``). After the ``with`` "
"statement's completion, the status is as it was before so message #6 appears "
"(like message #1) whereas message #7 doesn't (just like message #2)."
msgstr ""
#: howto/logging-cookbook.rst:2567
msgid "If we run the resulting script, the result is as follows:"
msgstr ""
#: howto/logging-cookbook.rst:2578
msgid ""
"If we run it again, but pipe ``stderr`` to ``/dev/null``, we see the "
"following, which is the only message written to ``stdout``:"
msgstr ""
#: howto/logging-cookbook.rst:2586
msgid "Once again, but piping ``stdout`` to ``/dev/null``, we get:"
msgstr ""
#: howto/logging-cookbook.rst:2596
msgid ""
"In this case, the message #5 printed to ``stdout`` doesn't appear, as "
"expected."
msgstr ""
#: howto/logging-cookbook.rst:2598
msgid ""
"Of course, the approach described here can be generalised, for example to "
"attach logging filters temporarily. Note that the above code works in Python "
"2 as well as Python 3."
msgstr ""
#: howto/logging-cookbook.rst:2606
msgid "A CLI application starter template"
msgstr ""
#: howto/logging-cookbook.rst:2608
msgid "Here's an example which shows how you can:"
msgstr ""
#: howto/logging-cookbook.rst:2610
msgid "Use a logging level based on command-line arguments"
msgstr ""
#: howto/logging-cookbook.rst:2611
msgid ""
"Dispatch to multiple subcommands in separate files, all logging at the same "
"level in a consistent way"
msgstr ""
#: howto/logging-cookbook.rst:2613
msgid "Make use of simple, minimal configuration"
msgstr ""
#: howto/logging-cookbook.rst:2615
msgid ""
"Suppose we have a command-line application whose job is to stop, start or "
"restart some services. This could be organised for the purposes of "
"illustration as a file ``app.py`` that is the main script for the "
"application, with individual commands implemented in ``start.py``, ``stop."
"py`` and ``restart.py``. Suppose further that we want to control the "
"verbosity of the application via a command-line argument, defaulting to "
"``logging.INFO``. Here's one way that ``app.py`` could be written::"
msgstr ""
#: howto/logging-cookbook.rst:2664
msgid ""
"And the ``start``, ``stop`` and ``restart`` commands can be implemented in "
"separate modules, like so for starting::"
msgstr ""
#: howto/logging-cookbook.rst:2677
msgid "and thus for stopping::"
msgstr ""
#: howto/logging-cookbook.rst:2698
msgid "and similarly for restarting::"
msgstr ""
#: howto/logging-cookbook.rst:2719
msgid ""
"If we run this application with the default log level, we get output like "
"this:"
msgstr ""
#: howto/logging-cookbook.rst:2732
msgid ""
"The first word is the logging level, and the second word is the module or "
"package name of the place where the event was logged."
msgstr ""
#: howto/logging-cookbook.rst:2735
msgid ""
"If we change the logging level, then we can change the information sent to "
"the log. For example, if we want more information:"
msgstr ""
#: howto/logging-cookbook.rst:2752
msgid "And if we want less:"
msgstr ""
#: howto/logging-cookbook.rst:2760
msgid ""
"In this case, the commands don't print anything to the console, since "
"nothing at ``WARNING`` level or above is logged by them."
msgstr ""
#: howto/logging-cookbook.rst:2766
msgid "A Qt GUI for logging"
msgstr ""
#: howto/logging-cookbook.rst:2768
msgid ""
"A question that comes up from time to time is about how to log to a GUI "
"application. The `Qt <https://www.qt.io/>`_ framework is a popular cross-"
"platform UI framework with Python bindings using `PySide2 <https://pypi.org/"
"project/PySide2/>`_ or `PyQt5 <https://pypi.org/project/PyQt5/>`_ libraries."
msgstr ""
#: howto/logging-cookbook.rst:2774
msgid ""
"The following example shows how to log to a Qt GUI. This introduces a simple "
"``QtHandler`` class which takes a callable, which should be a slot in the "
"main thread that does GUI updates. A worker thread is also created to show "
"how you can log to the GUI from both the UI itself (via a button for manual "
"logging) as well as a worker thread doing work in the background (here, just "
"logging messages at random levels with random short delays in between)."
msgstr ""
#: howto/logging-cookbook.rst:2781
msgid ""
"The worker thread is implemented using Qt's ``QThread`` class rather than "
"the :mod:`threading` module, as there are circumstances where one has to use "
"``QThread``, which offers better integration with other ``Qt`` components."
msgstr ""
#: howto/logging-cookbook.rst:2785
msgid ""
"The code should work with recent releases of either ``PySide2`` or "
"``PyQt5``. You should be able to adapt the approach to earlier versions of "
"Qt. Please refer to the comments in the code snippet for more detailed "
"information."
msgstr ""
#: howto/logging-cookbook.rst:3002
msgid "Patterns to avoid"
msgstr ""
#: howto/logging-cookbook.rst:3004
msgid ""
"Although the preceding sections have described ways of doing things you "
"might need to do or deal with, it is worth mentioning some usage patterns "
"which are *unhelpful*, and which should therefore be avoided in most cases. "
"The following sections are in no particular order."
msgstr ""
#: howto/logging-cookbook.rst:3011
msgid "Opening the same log file multiple times"
msgstr ""
#: howto/logging-cookbook.rst:3013
msgid ""
"On Windows, you will generally not be able to open the same file multiple "
"times as this will lead to a \"file is in use by another process\" error. "
"However, on POSIX platforms you'll not get any errors if you open the same "
"file multiple times. This could be done accidentally, for example by:"
msgstr ""
#: howto/logging-cookbook.rst:3018
msgid ""
"Adding a file handler more than once which references the same file (e.g. by "
"a copy/paste/forget-to-change error)."
msgstr ""
#: howto/logging-cookbook.rst:3021
msgid ""
"Opening two files that look different, as they have different names, but are "
"the same because one is a symbolic link to the other."
msgstr ""
#: howto/logging-cookbook.rst:3024
msgid ""
"Forking a process, following which both parent and child have a reference to "
"the same file. This might be through use of the :mod:`multiprocessing` "
"module, for example."
msgstr ""
#: howto/logging-cookbook.rst:3028
msgid ""
"Opening a file multiple times might *appear* to work most of the time, but "
"can lead to a number of problems in practice:"
msgstr ""
#: howto/logging-cookbook.rst:3031
msgid ""
"Logging output can be garbled because multiple threads or processes try to "
"write to the same file. Although logging guards against concurrent use of "
"the same handler instance by multiple threads, there is no such protection "
"if concurrent writes are attempted by two different threads using two "
"different handler instances which happen to point to the same file."
msgstr ""
#: howto/logging-cookbook.rst:3037
msgid ""
"An attempt to delete a file (e.g. during file rotation) silently fails, "
"because there is another reference pointing to it. This can lead to "
"confusion and wasted debugging time - log entries end up in unexpected "
"places, or are lost altogether. Or a file that was supposed to be moved "
"remains in place, and grows in size unexpectedly despite size-based rotation "
"being supposedly in place."
msgstr ""
#: howto/logging-cookbook.rst:3044
msgid ""
"Use the techniques outlined in :ref:`multiple-processes` to circumvent such "
"issues."
msgstr ""
#: howto/logging-cookbook.rst:3048
msgid "Using loggers as attributes in a class or passing them as parameters"
msgstr ""
#: howto/logging-cookbook.rst:3050
msgid ""
"While there might be unusual cases where you'll need to do this, in general "
"there is no point because loggers are singletons. Code can always access a "
"given logger instance by name using ``logging.getLogger(name)``, so passing "
"instances around and holding them as instance attributes is pointless. Note "
"that in other languages such as Java and C#, loggers are often static class "
"attributes. However, this pattern doesn't make sense in Python, where the "
"module (and not the class) is the unit of software decomposition."
msgstr ""
#: howto/logging-cookbook.rst:3060
msgid ""
"Adding handlers other than :class:`NullHandler` to a logger in a library"
msgstr ""
#: howto/logging-cookbook.rst:3062
msgid ""
"Configuring logging by adding handlers, formatters and filters is the "
"responsibility of the application developer, not the library developer. If "
"you are maintaining a library, ensure that you don't add handlers to any of "
"your loggers other than a :class:`~logging.NullHandler` instance."
msgstr ""
#: howto/logging-cookbook.rst:3069
msgid "Creating a lot of loggers"
msgstr ""
#: howto/logging-cookbook.rst:3071
msgid ""
"Loggers are singletons that are never freed during a script execution, and "
"so creating lots of loggers will use up memory which can't then be freed. "
"Rather than create a logger per e.g. file processed or network connection "
"made, use the :ref:`existing mechanisms <context-info>` for passing "
"contextual information into your logs and restrict the loggers created to "
"those describing areas within your application (generally modules, but "
"occasionally slightly more fine-grained than that)."
msgstr ""