# SOME DESCRIPTIVE TITLE. # Copyright (C) 2001-2016, Python Software Foundation # This file is distributed under the same license as the Python package. # FIRST AUTHOR , YEAR. # msgid "" msgstr "" "Project-Id-Version: Python 3.6\n" "Report-Msgid-Bugs-To: \n" "POT-Creation-Date: 2017-12-01 07:43+0100\n" "PO-Revision-Date: 2017-08-10 00:58+0200\n" "Last-Translator: Julien Palard \n" "Language-Team: \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 1.8.11\n" #: ../Doc/howto/regex.rst:5 msgid "Regular Expression HOWTO" msgstr "" #: ../Doc/howto/regex.rst:0 msgid "Author" msgstr "" #: ../Doc/howto/regex.rst:7 msgid "A.M. Kuchling " msgstr "" #: ../Doc/howto/regex.rst:18 msgid "" "This document is an introductory tutorial to using regular expressions in " "Python with the :mod:`re` module. It provides a gentler introduction than " "the corresponding section in the Library Reference." msgstr "" #: ../Doc/howto/regex.rst:24 msgid "Introduction" msgstr "Introduction" #: ../Doc/howto/regex.rst:26 msgid "" "Regular expressions (called REs, or regexes, or regex patterns) are " "essentially a tiny, highly specialized programming language embedded inside " "Python and made available through the :mod:`re` module. Using this little " "language, you specify the rules for the set of possible strings that you " "want to match; this set might contain English sentences, or e-mail " "addresses, or TeX commands, or anything you like. You can then ask " "questions such as \"Does this string match the pattern?\", or \"Is there a " "match for the pattern anywhere in this string?\". You can also use REs to " "modify a string or to split it apart in various ways." msgstr "" #: ../Doc/howto/regex.rst:35 msgid "" "Regular expression patterns are compiled into a series of bytecodes which " "are then executed by a matching engine written in C. For advanced use, it " "may be necessary to pay careful attention to how the engine will execute a " "given RE, and write the RE in a certain way in order to produce bytecode " "that runs faster. Optimization isn't covered in this document, because it " "requires that you have a good understanding of the matching engine's " "internals." msgstr "" #: ../Doc/howto/regex.rst:42 msgid "" "The regular expression language is relatively small and restricted, so not " "all possible string processing tasks can be done using regular expressions. " "There are also tasks that *can* be done with regular expressions, but the " "expressions turn out to be very complicated. In these cases, you may be " "better off writing Python code to do the processing; while Python code will " "be slower than an elaborate regular expression, it will also probably be " "more understandable." msgstr "" #: ../Doc/howto/regex.rst:51 msgid "Simple Patterns" msgstr "" #: ../Doc/howto/regex.rst:53 msgid "" "We'll start by learning about the simplest possible regular expressions. " "Since regular expressions are used to operate on strings, we'll begin with " "the most common task: matching characters." msgstr "" #: ../Doc/howto/regex.rst:57 msgid "" "For a detailed explanation of the computer science underlying regular " "expressions (deterministic and non-deterministic finite automata), you can " "refer to almost any textbook on writing compilers." msgstr "" #: ../Doc/howto/regex.rst:63 msgid "Matching Characters" msgstr "" #: ../Doc/howto/regex.rst:65 msgid "" "Most letters and characters will simply match themselves. For example, the " "regular expression ``test`` will match the string ``test`` exactly. (You " "can enable a case-insensitive mode that would let this RE match ``Test`` or " "``TEST`` as well; more about this later.)" msgstr "" #: ../Doc/howto/regex.rst:70 msgid "" "There are exceptions to this rule; some characters are special :dfn:" "`metacharacters`, and don't match themselves. Instead, they signal that " "some out-of-the-ordinary thing should be matched, or they affect other " "portions of the RE by repeating them or changing their meaning. Much of " "this document is devoted to discussing various metacharacters and what they " "do." msgstr "" #: ../Doc/howto/regex.rst:76 msgid "" "Here's a complete list of the metacharacters; their meanings will be " "discussed in the rest of this HOWTO." msgstr "" #: ../Doc/howto/regex.rst:83 msgid "" "The first metacharacters we'll look at are ``[`` and ``]``. They're used for " "specifying a character class, which is a set of characters that you wish to " "match. Characters can be listed individually, or a range of characters can " "be indicated by giving two characters and separating them by a ``'-'``. For " "example, ``[abc]`` will match any of the characters ``a``, ``b``, or ``c``; " "this is the same as ``[a-c]``, which uses a range to express the same set of " "characters. If you wanted to match only lowercase letters, your RE would be " "``[a-z]``." msgstr "" #: ../Doc/howto/regex.rst:92 msgid "" "Metacharacters are not active inside classes. For example, ``[akm$]`` will " "match any of the characters ``'a'``, ``'k'``, ``'m'``, or ``'$'``; ``'$'`` " "is usually a metacharacter, but inside a character class it's stripped of " "its special nature." msgstr "" #: ../Doc/howto/regex.rst:97 msgid "" "You can match the characters not listed within the class by :dfn:" "`complementing` the set. This is indicated by including a ``'^'`` as the " "first character of the class; ``'^'`` outside a character class will simply " "match the ``'^'`` character. For example, ``[^5]`` will match any character " "except ``'5'``." msgstr "" #: ../Doc/howto/regex.rst:102 msgid "" "Perhaps the most important metacharacter is the backslash, ``\\``. As in " "Python string literals, the backslash can be followed by various characters " "to signal various special sequences. It's also used to escape all the " "metacharacters so you can still match them in patterns; for example, if you " "need to match a ``[`` or ``\\``, you can precede them with a backslash to " "remove their special meaning: ``\\[`` or ``\\\\``." msgstr "" #: ../Doc/howto/regex.rst:109 msgid "" "Some of the special sequences beginning with ``'\\'`` represent predefined " "sets of characters that are often useful, such as the set of digits, the set " "of letters, or the set of anything that isn't whitespace." msgstr "" #: ../Doc/howto/regex.rst:114 msgid "" "Let's take an example: ``\\w`` matches any alphanumeric character. If the " "regex pattern is expressed in bytes, this is equivalent to the class ``[a-zA-" "Z0-9_]``. If the regex pattern is a string, ``\\w`` will match all the " "characters marked as letters in the Unicode database provided by the :mod:" "`unicodedata` module. You can use the more restricted definition of ``\\w`` " "in a string pattern by supplying the :const:`re.ASCII` flag when compiling " "the regular expression." msgstr "" #: ../Doc/howto/regex.rst:122 msgid "" "The following list of special sequences isn't complete. For a complete list " "of sequences and expanded class definitions for Unicode string patterns, see " "the last part of :ref:`Regular Expression Syntax ` in the " "Standard Library reference. In general, the Unicode versions match any " "character that's in the appropriate category in the Unicode database." msgstr "" #: ../Doc/howto/regex.rst:130 msgid "``\\d``" msgstr "``\\d``" #: ../Doc/howto/regex.rst:130 msgid "Matches any decimal digit; this is equivalent to the class ``[0-9]``." msgstr "" #: ../Doc/howto/regex.rst:133 msgid "``\\D``" msgstr "``\\D``" #: ../Doc/howto/regex.rst:133 msgid "" "Matches any non-digit character; this is equivalent to the class ``[^0-9]``." msgstr "" #: ../Doc/howto/regex.rst:137 msgid "``\\s``" msgstr "``\\s``" #: ../Doc/howto/regex.rst:136 msgid "" "Matches any whitespace character; this is equivalent to the class ``[ \\t\\n" "\\r\\f\\v]``." msgstr "" #: ../Doc/howto/regex.rst:141 msgid "``\\S``" msgstr "``\\S``" #: ../Doc/howto/regex.rst:140 msgid "" "Matches any non-whitespace character; this is equivalent to the class ``[^ " "\\t\\n\\r\\f\\v]``." msgstr "" #: ../Doc/howto/regex.rst:145 msgid "``\\w``" msgstr "``\\w``" #: ../Doc/howto/regex.rst:144 msgid "" "Matches any alphanumeric character; this is equivalent to the class ``[a-zA-" "Z0-9_]``." msgstr "" #: ../Doc/howto/regex.rst:149 msgid "``\\W``" msgstr "``\\W``" #: ../Doc/howto/regex.rst:148 msgid "" "Matches any non-alphanumeric character; this is equivalent to the class " "``[^a-zA-Z0-9_]``." msgstr "" #: ../Doc/howto/regex.rst:151 msgid "" "These sequences can be included inside a character class. For example, " "``[\\s,.]`` is a character class that will match any whitespace character, " "or ``','`` or ``'.'``." msgstr "" #: ../Doc/howto/regex.rst:155 msgid "" "The final metacharacter in this section is ``.``. It matches anything " "except a newline character, and there's an alternate mode (:const:`re." "DOTALL`) where it will match even a newline. ``.`` is often used where you " "want to match \"any character\"." msgstr "" #: ../Doc/howto/regex.rst:162 msgid "Repeating Things" msgstr "" #: ../Doc/howto/regex.rst:164 msgid "" "Being able to match varying sets of characters is the first thing regular " "expressions can do that isn't already possible with the methods available on " "strings. However, if that was the only additional capability of regexes, " "they wouldn't be much of an advance. Another capability is that you can " "specify that portions of the RE must be repeated a certain number of times." msgstr "" #: ../Doc/howto/regex.rst:170 msgid "" "The first metacharacter for repeating things that we'll look at is ``*``. " "``*`` doesn't match the literal character ``'*'``; instead, it specifies " "that the previous character can be matched zero or more times, instead of " "exactly once." msgstr "" #: ../Doc/howto/regex.rst:174 msgid "" "For example, ``ca*t`` will match ``'ct'`` (0 ``'a'`` characters), ``'cat'`` " "(1 ``'a'``), ``'caaat'`` (3 ``'a'`` characters), and so forth." msgstr "" #: ../Doc/howto/regex.rst:177 msgid "" "Repetitions such as ``*`` are :dfn:`greedy`; when repeating a RE, the " "matching engine will try to repeat it as many times as possible. If later " "portions of the pattern don't match, the matching engine will then back up " "and try again with fewer repetitions." msgstr "" #: ../Doc/howto/regex.rst:182 msgid "" "A step-by-step example will make this more obvious. Let's consider the " "expression ``a[bcd]*b``. This matches the letter ``'a'``, zero or more " "letters from the class ``[bcd]``, and finally ends with a ``'b'``. Now " "imagine matching this RE against the string ``'abcbd'``." msgstr "" #: ../Doc/howto/regex.rst:188 msgid "Step" msgstr "" #: ../Doc/howto/regex.rst:188 msgid "Matched" msgstr "" #: ../Doc/howto/regex.rst:188 msgid "Explanation" msgstr "" #: ../Doc/howto/regex.rst:190 msgid "1" msgstr "1" #: ../Doc/howto/regex.rst:190 msgid "``a``" msgstr "" #: ../Doc/howto/regex.rst:190 msgid "The ``a`` in the RE matches." msgstr "" #: ../Doc/howto/regex.rst:192 msgid "2" msgstr "2" #: ../Doc/howto/regex.rst:192 msgid "``abcbd``" msgstr "" #: ../Doc/howto/regex.rst:192 msgid "" "The engine matches ``[bcd]*``, going as far as it can, which is to the end " "of the string." msgstr "" #: ../Doc/howto/regex.rst:196 msgid "3" msgstr "3" #: ../Doc/howto/regex.rst:196 ../Doc/howto/regex.rst:204 msgid "*Failure*" msgstr "" #: ../Doc/howto/regex.rst:196 msgid "" "The engine tries to match ``b``, but the current position is at the end of " "the string, so it fails." msgstr "" #: ../Doc/howto/regex.rst:201 msgid "4" msgstr "4" #: ../Doc/howto/regex.rst:201 ../Doc/howto/regex.rst:212 msgid "``abcb``" msgstr "" #: ../Doc/howto/regex.rst:201 msgid "Back up, so that ``[bcd]*`` matches one less character." msgstr "" #: ../Doc/howto/regex.rst:204 msgid "5" msgstr "5" #: ../Doc/howto/regex.rst:204 msgid "" "Try ``b`` again, but the current position is at the last character, which is " "a ``'d'``." msgstr "" #: ../Doc/howto/regex.rst:208 ../Doc/howto/regex.rst:212 msgid "6" msgstr "6" #: ../Doc/howto/regex.rst:208 msgid "``abc``" msgstr "" #: ../Doc/howto/regex.rst:208 msgid "Back up again, so that ``[bcd]*`` is only matching ``bc``." msgstr "" #: ../Doc/howto/regex.rst:212 msgid "" "Try ``b`` again. This time the character at the current position is " "``'b'``, so it succeeds." msgstr "" #: ../Doc/howto/regex.rst:218 msgid "" "The end of the RE has now been reached, and it has matched ``'abcb'``. This " "demonstrates how the matching engine goes as far as it can at first, and if " "no match is found it will then progressively back up and retry the rest of " "the RE again and again. It will back up until it has tried zero matches for " "``[bcd]*``, and if that subsequently fails, the engine will conclude that " "the string doesn't match the RE at all." msgstr "" #: ../Doc/howto/regex.rst:225 msgid "" "Another repeating metacharacter is ``+``, which matches one or more times. " "Pay careful attention to the difference between ``*`` and ``+``; ``*`` " "matches *zero* or more times, so whatever's being repeated may not be " "present at all, while ``+`` requires at least *one* occurrence. To use a " "similar example, ``ca+t`` will match ``'cat'`` (1 ``'a'``), ``'caaat'`` (3 " "``'a'``\\ s), but won't match ``'ct'``." msgstr "" #: ../Doc/howto/regex.rst:232 msgid "" "There are two more repeating qualifiers. The question mark character, ``?" "``, matches either once or zero times; you can think of it as marking " "something as being optional. For example, ``home-?brew`` matches either " "``'homebrew'`` or ``'home-brew'``." msgstr "" #: ../Doc/howto/regex.rst:237 msgid "" "The most complicated repeated qualifier is ``{m,n}``, where *m* and *n* are " "decimal integers. This qualifier means there must be at least *m* " "repetitions, and at most *n*. For example, ``a/{1,3}b`` will match ``'a/" "b'``, ``'a//b'``, and ``'a///b'``. It won't match ``'ab'``, which has no " "slashes, or ``'a////b'``, which has four." msgstr "" #: ../Doc/howto/regex.rst:243 msgid "" "You can omit either *m* or *n*; in that case, a reasonable value is assumed " "for the missing value. Omitting *m* is interpreted as a lower limit of 0, " "while omitting *n* results in an upper bound of infinity." msgstr "" #: ../Doc/howto/regex.rst:247 msgid "" "Readers of a reductionist bent may notice that the three other qualifiers " "can all be expressed using this notation. ``{0,}`` is the same as ``*``, " "``{1,}`` is equivalent to ``+``, and ``{0,1}`` is the same as ``?``. It's " "better to use ``*``, ``+``, or ``?`` when you can, simply because they're " "shorter and easier to read." msgstr "" #: ../Doc/howto/regex.rst:255 msgid "Using Regular Expressions" msgstr "" #: ../Doc/howto/regex.rst:257 msgid "" "Now that we've looked at some simple regular expressions, how do we actually " "use them in Python? The :mod:`re` module provides an interface to the " "regular expression engine, allowing you to compile REs into objects and then " "perform matches with them." msgstr "" #: ../Doc/howto/regex.rst:264 msgid "Compiling Regular Expressions" msgstr "" #: ../Doc/howto/regex.rst:266 msgid "" "Regular expressions are compiled into pattern objects, which have methods " "for various operations such as searching for pattern matches or performing " "string substitutions. ::" msgstr "" #: ../Doc/howto/regex.rst:275 msgid "" ":func:`re.compile` also accepts an optional *flags* argument, used to enable " "various special features and syntax variations. We'll go over the available " "settings later, but for now a single example will do::" msgstr "" #: ../Doc/howto/regex.rst:281 msgid "" "The RE is passed to :func:`re.compile` as a string. REs are handled as " "strings because regular expressions aren't part of the core Python language, " "and no special syntax was created for expressing them. (There are " "applications that don't need REs at all, so there's no need to bloat the " "language specification by including them.) Instead, the :mod:`re` module is " "simply a C extension module included with Python, just like the :mod:" "`socket` or :mod:`zlib` modules." msgstr "" #: ../Doc/howto/regex.rst:288 msgid "" "Putting REs in strings keeps the Python language simpler, but has one " "disadvantage which is the topic of the next section." msgstr "" #: ../Doc/howto/regex.rst:293 msgid "The Backslash Plague" msgstr "" #: ../Doc/howto/regex.rst:295 msgid "" "As stated earlier, regular expressions use the backslash character " "(``'\\'``) to indicate special forms or to allow special characters to be " "used without invoking their special meaning. This conflicts with Python's " "usage of the same character for the same purpose in string literals." msgstr "" #: ../Doc/howto/regex.rst:300 msgid "" "Let's say you want to write a RE that matches the string ``\\section``, " "which might be found in a LaTeX file. To figure out what to write in the " "program code, start with the desired string to be matched. Next, you must " "escape any backslashes and other metacharacters by preceding them with a " "backslash, resulting in the string ``\\\\section``. The resulting string " "that must be passed to :func:`re.compile` must be ``\\\\section``. However, " "to express this as a Python string literal, both backslashes must be escaped " "*again*." msgstr "" #: ../Doc/howto/regex.rst:309 msgid "Characters" msgstr "Caractères" #: ../Doc/howto/regex.rst:309 msgid "Stage" msgstr "" #: ../Doc/howto/regex.rst:311 msgid "``\\section``" msgstr "" #: ../Doc/howto/regex.rst:311 msgid "Text string to be matched" msgstr "" #: ../Doc/howto/regex.rst:313 msgid "``\\\\section``" msgstr "" #: ../Doc/howto/regex.rst:313 msgid "Escaped backslash for :func:`re.compile`" msgstr "" #: ../Doc/howto/regex.rst:315 ../Doc/howto/regex.rst:335 msgid "``\"\\\\\\\\section\"``" msgstr "" #: ../Doc/howto/regex.rst:315 msgid "Escaped backslashes for a string literal" msgstr "" #: ../Doc/howto/regex.rst:318 msgid "" "In short, to match a literal backslash, one has to write ``'\\\\\\\\'`` as " "the RE string, because the regular expression must be ``\\\\``, and each " "backslash must be expressed as ``\\\\`` inside a regular Python string " "literal. In REs that feature backslashes repeatedly, this leads to lots of " "repeated backslashes and makes the resulting strings difficult to understand." msgstr "" #: ../Doc/howto/regex.rst:324 msgid "" "The solution is to use Python's raw string notation for regular expressions; " "backslashes are not handled in any special way in a string literal prefixed " "with ``'r'``, so ``r\"\\n\"`` is a two-character string containing ``'\\'`` " "and ``'n'``, while ``\"\\n\"`` is a one-character string containing a " "newline. Regular expressions will often be written in Python code using this " "raw string notation." msgstr "" #: ../Doc/howto/regex.rst:331 msgid "Regular String" msgstr "" #: ../Doc/howto/regex.rst:331 msgid "Raw string" msgstr "" #: ../Doc/howto/regex.rst:333 msgid "``\"ab*\"``" msgstr "" #: ../Doc/howto/regex.rst:333 msgid "``r\"ab*\"``" msgstr "" #: ../Doc/howto/regex.rst:335 msgid "``r\"\\\\section\"``" msgstr "" #: ../Doc/howto/regex.rst:337 msgid "``\"\\\\w+\\\\s+\\\\1\"``" msgstr "" #: ../Doc/howto/regex.rst:337 msgid "``r\"\\w+\\s+\\1\"``" msgstr "" #: ../Doc/howto/regex.rst:342 msgid "Performing Matches" msgstr "" #: ../Doc/howto/regex.rst:344 msgid "" "Once you have an object representing a compiled regular expression, what do " "you do with it? Pattern objects have several methods and attributes. Only " "the most significant ones will be covered here; consult the :mod:`re` docs " "for a complete listing." msgstr "" #: ../Doc/howto/regex.rst:350 ../Doc/howto/regex.rst:408 #: ../Doc/howto/regex.rst:1039 msgid "Method/Attribute" msgstr "" #: ../Doc/howto/regex.rst:350 ../Doc/howto/regex.rst:408 #: ../Doc/howto/regex.rst:1039 msgid "Purpose" msgstr "" #: ../Doc/howto/regex.rst:352 msgid "``match()``" msgstr "" #: ../Doc/howto/regex.rst:352 msgid "Determine if the RE matches at the beginning of the string." msgstr "" #: ../Doc/howto/regex.rst:355 msgid "``search()``" msgstr "" #: ../Doc/howto/regex.rst:355 msgid "Scan through a string, looking for any location where this RE matches." msgstr "" #: ../Doc/howto/regex.rst:358 msgid "``findall()``" msgstr "" #: ../Doc/howto/regex.rst:358 msgid "Find all substrings where the RE matches, and returns them as a list." msgstr "" #: ../Doc/howto/regex.rst:361 msgid "``finditer()``" msgstr "" #: ../Doc/howto/regex.rst:361 msgid "" "Find all substrings where the RE matches, and returns them as an :term:" "`iterator`." msgstr "" #: ../Doc/howto/regex.rst:365 msgid "" ":meth:`~re.pattern.match` and :meth:`~re.pattern.search` return ``None`` if " "no match can be found. If they're successful, a :ref:`match object ` instance is returned, containing information about the match: " "where it starts and ends, the substring it matched, and more." msgstr "" #: ../Doc/howto/regex.rst:370 msgid "" "You can learn about this by interactively experimenting with the :mod:`re` " "module. If you have :mod:`tkinter` available, you may also want to look at :" "source:`Tools/demo/redemo.py`, a demonstration program included with the " "Python distribution. It allows you to enter REs and strings, and displays " "whether the RE matches or fails. :file:`redemo.py` can be quite useful when " "trying to debug a complicated RE." msgstr "" #: ../Doc/howto/regex.rst:377 msgid "" "This HOWTO uses the standard Python interpreter for its examples. First, run " "the Python interpreter, import the :mod:`re` module, and compile a RE::" msgstr "" #: ../Doc/howto/regex.rst:385 msgid "" "Now, you can try matching various strings against the RE ``[a-z]+``. An " "empty string shouldn't match at all, since ``+`` means 'one or more " "repetitions'. :meth:`~re.pattern.match` should return ``None`` in this case, " "which will cause the interpreter to print no output. You can explicitly " "print the result of :meth:`!match` to make this clear. ::" msgstr "" #: ../Doc/howto/regex.rst:395 msgid "" "Now, let's try it on a string that it should match, such as ``tempo``. In " "this case, :meth:`~re.pattern.match` will return a :ref:`match object `, so you should store the result in a variable for later use. ::" msgstr "" #: ../Doc/howto/regex.rst:403 msgid "" "Now you can query the :ref:`match object ` for information " "about the matching string. Match object instances also have several methods " "and attributes; the most important ones are:" msgstr "" #: ../Doc/howto/regex.rst:410 msgid "``group()``" msgstr "" #: ../Doc/howto/regex.rst:410 msgid "Return the string matched by the RE" msgstr "" #: ../Doc/howto/regex.rst:412 msgid "``start()``" msgstr "" #: ../Doc/howto/regex.rst:412 msgid "Return the starting position of the match" msgstr "" #: ../Doc/howto/regex.rst:414 msgid "``end()``" msgstr "" #: ../Doc/howto/regex.rst:414 msgid "Return the ending position of the match" msgstr "" #: ../Doc/howto/regex.rst:416 msgid "``span()``" msgstr "" #: ../Doc/howto/regex.rst:416 msgid "Return a tuple containing the (start, end) positions of the match" msgstr "" #: ../Doc/howto/regex.rst:420 msgid "Trying these methods will soon clarify their meaning::" msgstr "" #: ../Doc/howto/regex.rst:429 msgid "" ":meth:`~re.match.group` returns the substring that was matched by the RE. :" "meth:`~re.match.start` and :meth:`~re.match.end` return the starting and " "ending index of the match. :meth:`~re.match.span` returns both start and end " "indexes in a single tuple. Since the :meth:`~re.pattern.match` method only " "checks if the RE matches at the start of a string, :meth:`!start` will " "always be zero. However, the :meth:`~re.pattern.search` method of patterns " "scans through the string, so the match may not start at zero in that " "case. ::" msgstr "" #: ../Doc/howto/regex.rst:446 msgid "" "In actual programs, the most common style is to store the :ref:`match object " "` in a variable, and then check if it was ``None``. This " "usually looks like::" msgstr "" #: ../Doc/howto/regex.rst:457 msgid "" "Two pattern methods return all of the matches for a pattern. :meth:`~re." "pattern.findall` returns a list of matching strings::" msgstr "" #: ../Doc/howto/regex.rst:464 msgid "" ":meth:`~re.pattern.findall` has to create the entire list before it can be " "returned as the result. The :meth:`~re.pattern.finditer` method returns a " "sequence of :ref:`match object ` instances as an :term:" "`iterator`::" msgstr "" #: ../Doc/howto/regex.rst:480 msgid "Module-Level Functions" msgstr "" #: ../Doc/howto/regex.rst:482 msgid "" "You don't have to create a pattern object and call its methods; the :mod:" "`re` module also provides top-level functions called :func:`~re.match`, :" "func:`~re.search`, :func:`~re.findall`, :func:`~re.sub`, and so forth. " "These functions take the same arguments as the corresponding pattern method " "with the RE string added as the first argument, and still return either " "``None`` or a :ref:`match object ` instance. ::" msgstr "" #: ../Doc/howto/regex.rst:494 msgid "" "Under the hood, these functions simply create a pattern object for you and " "call the appropriate method on it. They also store the compiled object in a " "cache, so future calls using the same RE won't need to parse the pattern " "again and again." msgstr "" #: ../Doc/howto/regex.rst:499 msgid "" "Should you use these module-level functions, or should you get the pattern " "and call its methods yourself? If you're accessing a regex within a loop, " "pre-compiling it will save a few function calls. Outside of loops, there's " "not much difference thanks to the internal cache." msgstr "" #: ../Doc/howto/regex.rst:507 msgid "Compilation Flags" msgstr "" #: ../Doc/howto/regex.rst:509 msgid "" "Compilation flags let you modify some aspects of how regular expressions " "work. Flags are available in the :mod:`re` module under two names, a long " "name such as :const:`IGNORECASE` and a short, one-letter form such as :const:" "`I`. (If you're familiar with Perl's pattern modifiers, the one-letter " "forms use the same letters; the short form of :const:`re.VERBOSE` is :const:" "`re.X`, for example.) Multiple flags can be specified by bitwise OR-ing " "them; ``re.I | re.M`` sets both the :const:`I` and :const:`M` flags, for " "example." msgstr "" #: ../Doc/howto/regex.rst:517 msgid "" "Here's a table of the available flags, followed by a more detailed " "explanation of each one." msgstr "" #: ../Doc/howto/regex.rst:521 msgid "Flag" msgstr "Option" #: ../Doc/howto/regex.rst:521 msgid "Meaning" msgstr "Signification" #: ../Doc/howto/regex.rst:523 msgid ":const:`ASCII`, :const:`A`" msgstr "" #: ../Doc/howto/regex.rst:523 msgid "" "Makes several escapes like ``\\w``, ``\\b``, ``\\s`` and ``\\d`` match only " "on ASCII characters with the respective property." msgstr "" #: ../Doc/howto/regex.rst:527 msgid ":const:`DOTALL`, :const:`S`" msgstr "" #: ../Doc/howto/regex.rst:527 msgid "Make ``.`` match any character, including newlines." msgstr "" #: ../Doc/howto/regex.rst:530 msgid ":const:`IGNORECASE`, :const:`I`" msgstr "" #: ../Doc/howto/regex.rst:530 msgid "Do case-insensitive matches." msgstr "" #: ../Doc/howto/regex.rst:532 msgid ":const:`LOCALE`, :const:`L`" msgstr "" #: ../Doc/howto/regex.rst:532 msgid "Do a locale-aware match." msgstr "" #: ../Doc/howto/regex.rst:534 msgid ":const:`MULTILINE`, :const:`M`" msgstr "" #: ../Doc/howto/regex.rst:534 msgid "Multi-line matching, affecting ``^`` and ``$``." msgstr "" #: ../Doc/howto/regex.rst:537 msgid ":const:`VERBOSE`, :const:`X` (for 'extended')" msgstr "" #: ../Doc/howto/regex.rst:537 msgid "" "Enable verbose REs, which can be organized more cleanly and understandably." msgstr "" #: ../Doc/howto/regex.rst:546 msgid "" "Perform case-insensitive matching; character class and literal strings will " "match letters by ignoring case. For example, ``[A-Z]`` will match lowercase " "letters, too. Full Unicode matching also works unless the :const:`ASCII` " "flag is used to disable non-ASCII matches. When the Unicode patterns ``[a-" "z]`` or ``[A-Z]`` are used in combination with the :const:`IGNORECASE` flag, " "they will match the 52 ASCII letters and 4 additional non-ASCII letters: " "'İ' (U+0130, Latin capital letter I with dot above), 'ı' (U+0131, Latin " "small letter dotless i), 'ſ' (U+017F, Latin small letter long s) and 'K' (U" "+212A, Kelvin sign). ``Spam`` will match ``'Spam'``, ``'spam'``, " "``'spAM'``, or ``'ſpam'`` (the latter is matched only in Unicode mode). This " "lowercasing doesn't take the current locale into account; it will if you " "also set the :const:`LOCALE` flag." msgstr "" #: ../Doc/howto/regex.rst:564 msgid "" "Make ``\\w``, ``\\W``, ``\\b``, ``\\B`` and case-insensitive matching " "dependent on the current locale instead of the Unicode database." msgstr "" #: ../Doc/howto/regex.rst:567 msgid "" "Locales are a feature of the C library intended to help in writing programs " "that take account of language differences. For example, if you're " "processing encoded French text, you'd want to be able to write ``\\w+`` to " "match words, but ``\\w`` only matches the character class ``[A-Za-z]`` in " "bytes patterns; it won't match bytes corresponding to ``é`` or ``ç``. If " "your system is configured properly and a French locale is selected, certain " "C functions will tell the program that the byte corresponding to ``é`` " "should also be considered a letter. Setting the :const:`LOCALE` flag when " "compiling a regular expression will cause the resulting compiled object to " "use these C functions for ``\\w``; this is slower, but also enables ``\\w+`` " "to match French words as you'd expect. The use of this flag is discouraged " "in Python 3 as the locale mechanism is very unreliable, it only handles one " "\"culture\" at a time, and it only works with 8-bit locales. Unicode " "matching is already enabled by default in Python 3 for Unicode (str) " "patterns, and it is able to handle different locales/languages." msgstr "" #: ../Doc/howto/regex.rst:589 msgid "" "(``^`` and ``$`` haven't been explained yet; they'll be introduced in " "section :ref:`more-metacharacters`.)" msgstr "" #: ../Doc/howto/regex.rst:592 msgid "" "Usually ``^`` matches only at the beginning of the string, and ``$`` matches " "only at the end of the string and immediately before the newline (if any) at " "the end of the string. When this flag is specified, ``^`` matches at the " "beginning of the string and at the beginning of each line within the string, " "immediately following each newline. Similarly, the ``$`` metacharacter " "matches either at the end of the string and at the end of each line " "(immediately preceding each newline)." msgstr "" #: ../Doc/howto/regex.rst:605 msgid "" "Makes the ``'.'`` special character match any character at all, including a " "newline; without this flag, ``'.'`` will match anything *except* a newline." msgstr "" #: ../Doc/howto/regex.rst:613 msgid "" "Make ``\\w``, ``\\W``, ``\\b``, ``\\B``, ``\\s`` and ``\\S`` perform ASCII-" "only matching instead of full Unicode matching. This is only meaningful for " "Unicode patterns, and is ignored for byte patterns." msgstr "" #: ../Doc/howto/regex.rst:622 msgid "" "This flag allows you to write regular expressions that are more readable by " "granting you more flexibility in how you can format them. When this flag " "has been specified, whitespace within the RE string is ignored, except when " "the whitespace is in a character class or preceded by an unescaped " "backslash; this lets you organize and indent the RE more clearly. This flag " "also lets you put comments within a RE that will be ignored by the engine; " "comments are marked by a ``'#'`` that's neither in a character class or " "preceded by an unescaped backslash." msgstr "" #: ../Doc/howto/regex.rst:631 msgid "" "For example, here's a RE that uses :const:`re.VERBOSE`; see how much easier " "it is to read? ::" msgstr "" #: ../Doc/howto/regex.rst:644 msgid "Without the verbose setting, the RE would look like this::" msgstr "" #: ../Doc/howto/regex.rst:650 msgid "" "In the above example, Python's automatic concatenation of string literals " "has been used to break up the RE into smaller pieces, but it's still more " "difficult to understand than the version using :const:`re.VERBOSE`." msgstr "" #: ../Doc/howto/regex.rst:656 msgid "More Pattern Power" msgstr "" #: ../Doc/howto/regex.rst:658 msgid "" "So far we've only covered a part of the features of regular expressions. In " "this section, we'll cover some new metacharacters, and how to use groups to " "retrieve portions of the text that was matched." msgstr "" #: ../Doc/howto/regex.rst:666 msgid "More Metacharacters" msgstr "" #: ../Doc/howto/regex.rst:668 msgid "" "There are some metacharacters that we haven't covered yet. Most of them " "will be covered in this section." msgstr "" #: ../Doc/howto/regex.rst:671 msgid "" "Some of the remaining metacharacters to be discussed are :dfn:`zero-width " "assertions`. They don't cause the engine to advance through the string; " "instead, they consume no characters at all, and simply succeed or fail. For " "example, ``\\b`` is an assertion that the current position is located at a " "word boundary; the position isn't changed by the ``\\b`` at all. This means " "that zero-width assertions should never be repeated, because if they match " "once at a given location, they can obviously be matched an infinite number " "of times." msgstr "" #: ../Doc/howto/regex.rst:687 msgid "``|``" msgstr "" #: ../Doc/howto/regex.rst:680 msgid "" "Alternation, or the \"or\" operator. If *A* and *B* are regular " "expressions, ``A|B`` will match any string that matches either *A* or *B*. " "``|`` has very low precedence in order to make it work reasonably when " "you're alternating multi-character strings. ``Crow|Servo`` will match either " "``'Crow'`` or ``'Servo'``, not ``'Cro'``, a ``'w'`` or an ``'S'``, and " "``'ervo'``." msgstr "" #: ../Doc/howto/regex.rst:686 msgid "" "To match a literal ``'|'``, use ``\\|``, or enclose it inside a character " "class, as in ``[|]``." msgstr "" #: ../Doc/howto/regex.rst:702 msgid "``^``" msgstr "" #: ../Doc/howto/regex.rst:690 msgid "" "Matches at the beginning of lines. Unless the :const:`MULTILINE` flag has " "been set, this will only match at the beginning of the string. In :const:" "`MULTILINE` mode, this also matches immediately after each newline within " "the string." msgstr "" #: ../Doc/howto/regex.rst:694 msgid "" "For example, if you wish to match the word ``From`` only at the beginning of " "a line, the RE to use is ``^From``. ::" msgstr "" #: ../Doc/howto/regex.rst:702 msgid "To match a literal ``'^'``, use ``\\^``." msgstr "" #: ../Doc/howto/regex.rst:716 msgid "``$``" msgstr "" #: ../Doc/howto/regex.rst:705 msgid "" "Matches at the end of a line, which is defined as either the end of the " "string, or any location followed by a newline character. ::" msgstr "" #: ../Doc/howto/regex.rst:715 msgid "" "To match a literal ``'$'``, use ``\\$`` or enclose it inside a character " "class, as in ``[$]``." msgstr "" #: ../Doc/howto/regex.rst:722 msgid "``\\A``" msgstr "``\\A``" #: ../Doc/howto/regex.rst:719 msgid "" "Matches only at the start of the string. When not in :const:`MULTILINE` " "mode, ``\\A`` and ``^`` are effectively the same. In :const:`MULTILINE` " "mode, they're different: ``\\A`` still matches only at the beginning of the " "string, but ``^`` may match at any location inside the string that follows a " "newline character." msgstr "" #: ../Doc/howto/regex.rst:725 msgid "``\\Z``" msgstr "``\\Z``" #: ../Doc/howto/regex.rst:725 msgid "Matches only at the end of the string." msgstr "Correspond uniquement à la fin d'une chaîne de caractères." #: ../Doc/howto/regex.rst:760 msgid "``\\b``" msgstr "``\\b``" #: ../Doc/howto/regex.rst:728 msgid "" "Word boundary. This is a zero-width assertion that matches only at the " "beginning or end of a word. A word is defined as a sequence of alphanumeric " "characters, so the end of a word is indicated by whitespace or a non-" "alphanumeric character." msgstr "" #: ../Doc/howto/regex.rst:733 msgid "" "The following example matches ``class`` only when it's a complete word; it " "won't match when it's contained inside another word. ::" msgstr "" #: ../Doc/howto/regex.rst:744 msgid "" "There are two subtleties you should remember when using this special " "sequence. First, this is the worst collision between Python's string " "literals and regular expression sequences. In Python's string literals, ``" "\\b`` is the backspace character, ASCII value 8. If you're not using raw " "strings, then Python will convert the ``\\b`` to a backspace, and your RE " "won't match as you expect it to. The following example looks the same as our " "previous RE, but omits the ``'r'`` in front of the RE string. ::" msgstr "" #: ../Doc/howto/regex.rst:758 msgid "" "Second, inside a character class, where there's no use for this assertion, ``" "\\b`` represents the backspace character, for compatibility with Python's " "string literals." msgstr "" #: ../Doc/howto/regex.rst:765 msgid "``\\B``" msgstr "``\\B``" #: ../Doc/howto/regex.rst:763 msgid "" "Another zero-width assertion, this is the opposite of ``\\b``, only matching " "when the current position is not at a word boundary." msgstr "" #: ../Doc/howto/regex.rst:768 msgid "Grouping" msgstr "" #: ../Doc/howto/regex.rst:770 msgid "" "Frequently you need to obtain more information than just whether the RE " "matched or not. Regular expressions are often used to dissect strings by " "writing a RE divided into several subgroups which match different components " "of interest. For example, an RFC-822 header line is divided into a header " "name and a value, separated by a ``':'``, like this::" msgstr "" #: ../Doc/howto/regex.rst:781 msgid "" "This can be handled by writing a regular expression which matches an entire " "header line, and has one group which matches the header name, and another " "group which matches the header's value." msgstr "" #: ../Doc/howto/regex.rst:785 msgid "" "Groups are marked by the ``'('``, ``')'`` metacharacters. ``'('`` and " "``')'`` have much the same meaning as they do in mathematical expressions; " "they group together the expressions contained inside them, and you can " "repeat the contents of a group with a repeating qualifier, such as ``*``, ``" "+``, ``?``, or ``{m,n}``. For example, ``(ab)*`` will match zero or more " "repetitions of ``ab``. ::" msgstr "" #: ../Doc/howto/regex.rst:796 msgid "" "Groups indicated with ``'('``, ``')'`` also capture the starting and ending " "index of the text that they match; this can be retrieved by passing an " "argument to :meth:`~re.match.group`, :meth:`~re.match.start`, :meth:`~re." "match.end`, and :meth:`~re.match.span`. Groups are numbered starting with " "0. Group 0 is always present; it's the whole RE, so :ref:`match object " "` methods all have group 0 as their default argument. Later " "we'll see how to express groups that don't capture the span of text that " "they match. ::" msgstr "" #: ../Doc/howto/regex.rst:812 msgid "" "Subgroups are numbered from left to right, from 1 upward. Groups can be " "nested; to determine the number, just count the opening parenthesis " "characters, going from left to right. ::" msgstr "" #: ../Doc/howto/regex.rst:825 msgid "" ":meth:`~re.match.group` can be passed multiple group numbers at a time, in " "which case it will return a tuple containing the corresponding values for " "those groups. ::" msgstr "" #: ../Doc/howto/regex.rst:831 msgid "" "The :meth:`~re.match.groups` method returns a tuple containing the strings " "for all the subgroups, from 1 up to however many there are. ::" msgstr "" #: ../Doc/howto/regex.rst:837 msgid "" "Backreferences in a pattern allow you to specify that the contents of an " "earlier capturing group must also be found at the current location in the " "string. For example, ``\\1`` will succeed if the exact contents of group 1 " "can be found at the current position, and fails otherwise. Remember that " "Python's string literals also use a backslash followed by numbers to allow " "including arbitrary characters in a string, so be sure to use a raw string " "when incorporating backreferences in a RE." msgstr "" #: ../Doc/howto/regex.rst:845 msgid "For example, the following RE detects doubled words in a string. ::" msgstr "" #: ../Doc/howto/regex.rst:851 msgid "" "Backreferences like this aren't often useful for just searching through a " "string --- there are few text formats which repeat data in this way --- but " "you'll soon find out that they're *very* useful when performing string " "substitutions." msgstr "" #: ../Doc/howto/regex.rst:857 msgid "Non-capturing and Named Groups" msgstr "" #: ../Doc/howto/regex.rst:859 msgid "" "Elaborate REs may use many groups, both to capture substrings of interest, " "and to group and structure the RE itself. In complex REs, it becomes " "difficult to keep track of the group numbers. There are two features which " "help with this problem. Both of them use a common syntax for regular " "expression extensions, so we'll look at that first." msgstr "" #: ../Doc/howto/regex.rst:865 msgid "" "Perl 5 is well known for its powerful additions to standard regular " "expressions. For these new features the Perl developers couldn't choose new " "single-keystroke metacharacters or new special sequences beginning with ``" "\\`` without making Perl's regular expressions confusingly different from " "standard REs. If they chose ``&`` as a new metacharacter, for example, old " "expressions would be assuming that ``&`` was a regular character and " "wouldn't have escaped it by writing ``\\&`` or ``[&]``." msgstr "" #: ../Doc/howto/regex.rst:872 msgid "" "The solution chosen by the Perl developers was to use ``(?...)`` as the " "extension syntax. ``?`` immediately after a parenthesis was a syntax error " "because the ``?`` would have nothing to repeat, so this didn't introduce any " "compatibility problems. The characters immediately after the ``?`` " "indicate what extension is being used, so ``(?=foo)`` is one thing (a " "positive lookahead assertion) and ``(?:foo)`` is something else (a non-" "capturing group containing the subexpression ``foo``)." msgstr "" #: ../Doc/howto/regex.rst:880 msgid "" "Python supports several of Perl's extensions and adds an extension syntax to " "Perl's extension syntax. If the first character after the question mark is " "a ``P``, you know that it's an extension that's specific to Python." msgstr "" #: ../Doc/howto/regex.rst:885 msgid "" "Now that we've looked at the general extension syntax, we can return to the " "features that simplify working with groups in complex REs." msgstr "" #: ../Doc/howto/regex.rst:888 msgid "" "Sometimes you'll want to use a group to denote a part of a regular " "expression, but aren't interested in retrieving the group's contents. You " "can make this fact explicit by using a non-capturing group: ``(?:...)``, " "where you can replace the ``...`` with any other regular expression. ::" msgstr "" #: ../Doc/howto/regex.rst:900 msgid "" "Except for the fact that you can't retrieve the contents of what the group " "matched, a non-capturing group behaves exactly the same as a capturing " "group; you can put anything inside it, repeat it with a repetition " "metacharacter such as ``*``, and nest it within other groups (capturing or " "non-capturing). ``(?:...)`` is particularly useful when modifying an " "existing pattern, since you can add new groups without changing how all the " "other groups are numbered. It should be mentioned that there's no " "performance difference in searching between capturing and non-capturing " "groups; neither form is any faster than the other." msgstr "" #: ../Doc/howto/regex.rst:909 msgid "" "A more significant feature is named groups: instead of referring to them by " "numbers, groups can be referenced by a name." msgstr "" #: ../Doc/howto/regex.rst:912 msgid "" "The syntax for a named group is one of the Python-specific extensions: ``(?" "P...)``. *name* is, obviously, the name of the group. Named groups " "behave exactly like capturing groups, and additionally associate a name with " "a group. The :ref:`match object ` methods that deal with " "capturing groups all accept either integers that refer to the group by " "number or strings that contain the desired group's name. Named groups are " "still given numbers, so you can retrieve information about a group in two " "ways::" msgstr "" #: ../Doc/howto/regex.rst:927 msgid "" "Named groups are handy because they let you use easily-remembered names, " "instead of having to remember numbers. Here's an example RE from the :mod:" "`imaplib` module::" msgstr "" #: ../Doc/howto/regex.rst:938 msgid "" "It's obviously much easier to retrieve ``m.group('zonem')``, instead of " "having to remember to retrieve group 9." msgstr "" #: ../Doc/howto/regex.rst:941 msgid "" "The syntax for backreferences in an expression such as ``(...)\\1`` refers " "to the number of the group. There's naturally a variant that uses the group " "name instead of the number. This is another Python extension: ``(?P=name)`` " "indicates that the contents of the group called *name* should again be " "matched at the current point. The regular expression for finding doubled " "words, ``\\b(\\w+)\\s+\\1\\b`` can also be written as ``\\b(?P\\w+)\\s" "+(?P=word)\\b``::" msgstr "" #: ../Doc/howto/regex.rst:954 msgid "Lookahead Assertions" msgstr "" #: ../Doc/howto/regex.rst:956 msgid "" "Another zero-width assertion is the lookahead assertion. Lookahead " "assertions are available in both positive and negative form, and look like " "this:" msgstr "" #: ../Doc/howto/regex.rst:964 msgid "``(?=...)``" msgstr "``(?=...)``" #: ../Doc/howto/regex.rst:960 msgid "" "Positive lookahead assertion. This succeeds if the contained regular " "expression, represented here by ``...``, successfully matches at the current " "location, and fails otherwise. But, once the contained expression has been " "tried, the matching engine doesn't advance at all; the rest of the pattern " "is tried right where the assertion started." msgstr "" #: ../Doc/howto/regex.rst:969 msgid "``(?!...)``" msgstr "``(?!...)``" #: ../Doc/howto/regex.rst:967 msgid "" "Negative lookahead assertion. This is the opposite of the positive " "assertion; it succeeds if the contained expression *doesn't* match at the " "current position in the string." msgstr "" #: ../Doc/howto/regex.rst:971 msgid "" "To make this concrete, let's look at a case where a lookahead is useful. " "Consider a simple pattern to match a filename and split it apart into a base " "name and an extension, separated by a ``.``. For example, in ``news.rc``, " "``news`` is the base name, and ``rc`` is the filename's extension." msgstr "" #: ../Doc/howto/regex.rst:976 msgid "The pattern to match this is quite simple:" msgstr "" #: ../Doc/howto/regex.rst:978 msgid "``.*[.].*$``" msgstr "" #: ../Doc/howto/regex.rst:980 msgid "" "Notice that the ``.`` needs to be treated specially because it's a " "metacharacter, so it's inside a character class to only match that specific " "character. Also notice the trailing ``$``; this is added to ensure that all " "the rest of the string must be included in the extension. This regular " "expression matches ``foo.bar`` and ``autoexec.bat`` and ``sendmail.cf`` and " "``printers.conf``." msgstr "" #: ../Doc/howto/regex.rst:987 msgid "" "Now, consider complicating the problem a bit; what if you want to match " "filenames where the extension is not ``bat``? Some incorrect attempts:" msgstr "" #: ../Doc/howto/regex.rst:990 msgid "" "``.*[.][^b].*$`` The first attempt above tries to exclude ``bat`` by " "requiring that the first character of the extension is not a ``b``. This is " "wrong, because the pattern also doesn't match ``foo.bar``." msgstr "" #: ../Doc/howto/regex.rst:994 msgid "``.*[.]([^b]..|.[^a].|..[^t])$``" msgstr "" #: ../Doc/howto/regex.rst:996 msgid "" "The expression gets messier when you try to patch up the first solution by " "requiring one of the following cases to match: the first character of the " "extension isn't ``b``; the second character isn't ``a``; or the third " "character isn't ``t``. This accepts ``foo.bar`` and rejects ``autoexec." "bat``, but it requires a three-letter extension and won't accept a filename " "with a two-letter extension such as ``sendmail.cf``. We'll complicate the " "pattern again in an effort to fix it." msgstr "" #: ../Doc/howto/regex.rst:1004 msgid "``.*[.]([^b].?.?|.[^a]?.?|..?[^t]?)$``" msgstr "" #: ../Doc/howto/regex.rst:1006 msgid "" "In the third attempt, the second and third letters are all made optional in " "order to allow matching extensions shorter than three characters, such as " "``sendmail.cf``." msgstr "" #: ../Doc/howto/regex.rst:1010 msgid "" "The pattern's getting really complicated now, which makes it hard to read " "and understand. Worse, if the problem changes and you want to exclude both " "``bat`` and ``exe`` as extensions, the pattern would get even more " "complicated and confusing." msgstr "" #: ../Doc/howto/regex.rst:1015 msgid "A negative lookahead cuts through all this confusion:" msgstr "" #: ../Doc/howto/regex.rst:1017 msgid "" "``.*[.](?!bat$)[^.]*$`` The negative lookahead means: if the expression " "``bat`` doesn't match at this point, try the rest of the pattern; if ``bat" "$`` does match, the whole pattern will fail. The trailing ``$`` is required " "to ensure that something like ``sample.batch``, where the extension only " "starts with ``bat``, will be allowed. The ``[^.]*`` makes sure that the " "pattern works when there are multiple dots in the filename." msgstr "" #: ../Doc/howto/regex.rst:1024 msgid "" "Excluding another filename extension is now easy; simply add it as an " "alternative inside the assertion. The following pattern excludes filenames " "that end in either ``bat`` or ``exe``:" msgstr "" #: ../Doc/howto/regex.rst:1028 msgid "``.*[.](?!bat$|exe$)[^.]*$``" msgstr "" #: ../Doc/howto/regex.rst:1032 msgid "Modifying Strings" msgstr "" #: ../Doc/howto/regex.rst:1034 msgid "" "Up to this point, we've simply performed searches against a static string. " "Regular expressions are also commonly used to modify strings in various " "ways, using the following pattern methods:" msgstr "" #: ../Doc/howto/regex.rst:1041 msgid "``split()``" msgstr "" #: ../Doc/howto/regex.rst:1041 msgid "Split the string into a list, splitting it wherever the RE matches" msgstr "" #: ../Doc/howto/regex.rst:1044 msgid "``sub()``" msgstr "" #: ../Doc/howto/regex.rst:1044 msgid "" "Find all substrings where the RE matches, and replace them with a different " "string" msgstr "" #: ../Doc/howto/regex.rst:1047 msgid "``subn()``" msgstr "" #: ../Doc/howto/regex.rst:1047 msgid "" "Does the same thing as :meth:`!sub`, but returns the new string and the " "number of replacements" msgstr "" #: ../Doc/howto/regex.rst:1054 msgid "Splitting Strings" msgstr "" #: ../Doc/howto/regex.rst:1056 msgid "" "The :meth:`~re.pattern.split` method of a pattern splits a string apart " "wherever the RE matches, returning a list of the pieces. It's similar to " "the :meth:`~str.split` method of strings but provides much more generality " "in the delimiters that you can split by; string :meth:`!split` only supports " "splitting by whitespace or by a fixed string. As you'd expect, there's a " "module-level :func:`re.split` function, too." msgstr "" #: ../Doc/howto/regex.rst:1067 msgid "" "Split *string* by the matches of the regular expression. If capturing " "parentheses are used in the RE, then their contents will also be returned as " "part of the resulting list. If *maxsplit* is nonzero, at most *maxsplit* " "splits are performed." msgstr "" #: ../Doc/howto/regex.rst:1072 msgid "" "You can limit the number of splits made, by passing a value for *maxsplit*. " "When *maxsplit* is nonzero, at most *maxsplit* splits will be made, and the " "remainder of the string is returned as the final element of the list. In " "the following example, the delimiter is any sequence of non-alphanumeric " "characters. ::" msgstr "" #: ../Doc/howto/regex.rst:1084 msgid "" "Sometimes you're not only interested in what the text between delimiters is, " "but also need to know what the delimiter was. If capturing parentheses are " "used in the RE, then their values are also returned as part of the list. " "Compare the following calls::" msgstr "" #: ../Doc/howto/regex.rst:1096 msgid "" "The module-level function :func:`re.split` adds the RE to be used as the " "first argument, but is otherwise the same. ::" msgstr "" #: ../Doc/howto/regex.rst:1108 msgid "Search and Replace" msgstr "" #: ../Doc/howto/regex.rst:1110 msgid "" "Another common task is to find all the matches for a pattern, and replace " "them with a different string. The :meth:`~re.pattern.sub` method takes a " "replacement value, which can be either a string or a function, and the " "string to be processed." msgstr "" #: ../Doc/howto/regex.rst:1117 msgid "" "Returns the string obtained by replacing the leftmost non-overlapping " "occurrences of the RE in *string* by the replacement *replacement*. If the " "pattern isn't found, *string* is returned unchanged." msgstr "" #: ../Doc/howto/regex.rst:1121 msgid "" "The optional argument *count* is the maximum number of pattern occurrences " "to be replaced; *count* must be a non-negative integer. The default value " "of 0 means to replace all occurrences." msgstr "" #: ../Doc/howto/regex.rst:1125 msgid "" "Here's a simple example of using the :meth:`~re.pattern.sub` method. It " "replaces colour names with the word ``colour``::" msgstr "" #: ../Doc/howto/regex.rst:1134 msgid "" "The :meth:`~re.pattern.subn` method does the same work, but returns a 2-" "tuple containing the new string value and the number of replacements that " "were performed::" msgstr "" #: ../Doc/howto/regex.rst:1143 msgid "" "Empty matches are replaced only when they're not adjacent to a previous " "match. ::" msgstr "" #: ../Doc/howto/regex.rst:1150 msgid "" "If *replacement* is a string, any backslash escapes in it are processed. " "That is, ``\\n`` is converted to a single newline character, ``\\r`` is " "converted to a carriage return, and so forth. Unknown escapes such as ``" "\\&`` are left alone. Backreferences, such as ``\\6``, are replaced with the " "substring matched by the corresponding group in the RE. This lets you " "incorporate portions of the original text in the resulting replacement " "string." msgstr "" #: ../Doc/howto/regex.rst:1157 msgid "" "This example matches the word ``section`` followed by a string enclosed in " "``{``, ``}``, and changes ``section`` to ``subsection``::" msgstr "" #: ../Doc/howto/regex.rst:1164 msgid "" "There's also a syntax for referring to named groups as defined by the ``(?" "P...)`` syntax. ``\\g`` will use the substring matched by the " "group named ``name``, and ``\\g`` uses the corresponding group " "number. ``\\g<2>`` is therefore equivalent to ``\\2``, but isn't ambiguous " "in a replacement string such as ``\\g<2>0``. (``\\20`` would be interpreted " "as a reference to group 20, not a reference to group 2 followed by the " "literal character ``'0'``.) The following substitutions are all equivalent, " "but use all three variations of the replacement string. ::" msgstr "" #: ../Doc/howto/regex.rst:1181 msgid "" "*replacement* can also be a function, which gives you even more control. If " "*replacement* is a function, the function is called for every non-" "overlapping occurrence of *pattern*. On each call, the function is passed " "a :ref:`match object ` argument for the match and can use " "this information to compute the desired replacement string and return it." msgstr "" #: ../Doc/howto/regex.rst:1187 msgid "" "In the following example, the replacement function translates decimals into " "hexadecimal::" msgstr "" #: ../Doc/howto/regex.rst:1199 msgid "" "When using the module-level :func:`re.sub` function, the pattern is passed " "as the first argument. The pattern may be provided as an object or as a " "string; if you need to specify regular expression flags, you must either use " "a pattern object as the first parameter, or use embedded modifiers in the " "pattern string, e.g. ``sub(\"(?i)b+\", \"x\", \"bbbb BBBB\")`` returns ``'x " "x'``." msgstr "" #: ../Doc/howto/regex.rst:1207 msgid "Common Problems" msgstr "" #: ../Doc/howto/regex.rst:1209 msgid "" "Regular expressions are a powerful tool for some applications, but in some " "ways their behaviour isn't intuitive and at times they don't behave the way " "you may expect them to. This section will point out some of the most common " "pitfalls." msgstr "" #: ../Doc/howto/regex.rst:1215 msgid "Use String Methods" msgstr "" #: ../Doc/howto/regex.rst:1217 msgid "" "Sometimes using the :mod:`re` module is a mistake. If you're matching a " "fixed string, or a single character class, and you're not using any :mod:" "`re` features such as the :const:`~re.IGNORECASE` flag, then the full power " "of regular expressions may not be required. Strings have several methods for " "performing operations with fixed strings and they're usually much faster, " "because the implementation is a single small C loop that's been optimized " "for the purpose, instead of the large, more generalized regular expression " "engine." msgstr "" #: ../Doc/howto/regex.rst:1225 msgid "" "One example might be replacing a single fixed string with another one; for " "example, you might replace ``word`` with ``deed``. :func:`re.sub` seems " "like the function to use for this, but consider the :meth:`~str.replace` " "method. Note that :meth:`!replace` will also replace ``word`` inside words, " "turning ``swordfish`` into ``sdeedfish``, but the naive RE ``word`` would " "have done that, too. (To avoid performing the substitution on parts of " "words, the pattern would have to be ``\\bword\\b``, in order to require that " "``word`` have a word boundary on either side. This takes the job beyond :" "meth:`!replace`'s abilities.)" msgstr "" #: ../Doc/howto/regex.rst:1234 msgid "" "Another common task is deleting every occurrence of a single character from " "a string or replacing it with another single character. You might do this " "with something like ``re.sub('\\n', ' ', S)``, but :meth:`~str.translate` is " "capable of doing both tasks and will be faster than any regular expression " "operation can be." msgstr "" #: ../Doc/howto/regex.rst:1240 msgid "" "In short, before turning to the :mod:`re` module, consider whether your " "problem can be solved with a faster and simpler string method." msgstr "" #: ../Doc/howto/regex.rst:1245 msgid "match() versus search()" msgstr "" #: ../Doc/howto/regex.rst:1247 msgid "" "The :func:`~re.match` function only checks if the RE matches at the " "beginning of the string while :func:`~re.search` will scan forward through " "the string for a match. It's important to keep this distinction in mind. " "Remember, :func:`!match` will only report a successful match which will " "start at 0; if the match wouldn't start at zero, :func:`!match` will *not* " "report it. ::" msgstr "" #: ../Doc/howto/regex.rst:1258 msgid "" "On the other hand, :func:`~re.search` will scan forward through the string, " "reporting the first match it finds. ::" msgstr "" #: ../Doc/howto/regex.rst:1266 msgid "" "Sometimes you'll be tempted to keep using :func:`re.match`, and just add ``." "*`` to the front of your RE. Resist this temptation and use :func:`re." "search` instead. The regular expression compiler does some analysis of REs " "in order to speed up the process of looking for a match. One such analysis " "figures out what the first character of a match must be; for example, a " "pattern starting with ``Crow`` must match starting with a ``'C'``. The " "analysis lets the engine quickly scan through the string looking for the " "starting character, only trying the full match if a ``'C'`` is found." msgstr "" #: ../Doc/howto/regex.rst:1275 msgid "" "Adding ``.*`` defeats this optimization, requiring scanning to the end of " "the string and then backtracking to find a match for the rest of the RE. " "Use :func:`re.search` instead." msgstr "" #: ../Doc/howto/regex.rst:1281 msgid "Greedy versus Non-Greedy" msgstr "" #: ../Doc/howto/regex.rst:1283 msgid "" "When repeating a regular expression, as in ``a*``, the resulting action is " "to consume as much of the pattern as possible. This fact often bites you " "when you're trying to match a pair of balanced delimiters, such as the angle " "brackets surrounding an HTML tag. The naive pattern for matching a single " "HTML tag doesn't work because of the greedy nature of ``.*``. ::" msgstr "" #: ../Doc/howto/regex.rst:1297 msgid "" "The RE matches the ``'<'`` in ``''``, and the ``.*`` consumes the rest " "of the string. There's still more left in the RE, though, and the ``>`` " "can't match at the end of the string, so the regular expression engine has " "to backtrack character by character until it finds a match for the ``>``. " "The final match extends from the ``'<'`` in ``''`` to the ``'>'`` in " "``''``, which isn't what you want." msgstr "" #: ../Doc/howto/regex.rst:1304 msgid "" "In this case, the solution is to use the non-greedy qualifiers ``*?``, ``+?" "``, ``??``, or ``{m,n}?``, which match as *little* text as possible. In the " "above example, the ``'>'`` is tried immediately after the first ``'<'`` " "matches, and when it fails, the engine advances a character at a time, " "retrying the ``'>'`` at every step. This produces just the right result::" msgstr "" #: ../Doc/howto/regex.rst:1313 msgid "" "(Note that parsing HTML or XML with regular expressions is painful. Quick-" "and-dirty patterns will handle common cases, but HTML and XML have special " "cases that will break the obvious regular expression; by the time you've " "written a regular expression that handles all of the possible cases, the " "patterns will be *very* complicated. Use an HTML or XML parser module for " "such tasks.)" msgstr "" #: ../Doc/howto/regex.rst:1321 msgid "Using re.VERBOSE" msgstr "" #: ../Doc/howto/regex.rst:1323 msgid "" "By now you've probably noticed that regular expressions are a very compact " "notation, but they're not terribly readable. REs of moderate complexity can " "become lengthy collections of backslashes, parentheses, and metacharacters, " "making them difficult to read and understand." msgstr "" #: ../Doc/howto/regex.rst:1328 msgid "" "For such REs, specifying the :const:`re.VERBOSE` flag when compiling the " "regular expression can be helpful, because it allows you to format the " "regular expression more clearly." msgstr "" #: ../Doc/howto/regex.rst:1332 msgid "" "The ``re.VERBOSE`` flag has several effects. Whitespace in the regular " "expression that *isn't* inside a character class is ignored. This means " "that an expression such as ``dog | cat`` is equivalent to the less readable " "``dog|cat``, but ``[a b]`` will still match the characters ``'a'``, ``'b'``, " "or a space. In addition, you can also put comments inside a RE; comments " "extend from a ``#`` character to the next newline. When used with triple-" "quoted strings, this enables REs to be formatted more neatly::" msgstr "" #: ../Doc/howto/regex.rst:1349 msgid "This is far more readable than::" msgstr "" #: ../Doc/howto/regex.rst:1355 msgid "Feedback" msgstr "" #: ../Doc/howto/regex.rst:1357 msgid "" "Regular expressions are a complicated topic. Did this document help you " "understand them? Were there parts that were unclear, or Problems you " "encountered that weren't covered here? If so, please send suggestions for " "improvements to the author." msgstr "" #: ../Doc/howto/regex.rst:1362 msgid "" "The most complete book on regular expressions is almost certainly Jeffrey " "Friedl's Mastering Regular Expressions, published by O'Reilly. " "Unfortunately, it exclusively concentrates on Perl and Java's flavours of " "regular expressions, and doesn't contain any Python material at all, so it " "won't be useful as a reference for programming in Python. (The first " "edition covered Python's now-removed :mod:`!regex` module, which won't help " "you much.) Consider checking it out from your library." msgstr "" #~ msgid "Abstract" #~ msgstr "Résumé"