Detailed explanation of the usage of Python re module
Python’s re module is one of the core modules for regular expression operations. Commonly used methods are: 1. re.match, try to match the pattern from the starting position of the string; 2. re.search, search for the pattern in the string; 3. re.findall, return all content in the string that matches the pattern list; 4. re.finditer, returns an iterator of all content matching the pattern in the string; 5. re.split, splits the string into multiple parts according to the matching splitting rules, etc.
Python’s re module contains the following commonly used methods:
re.match(pattern, string): From the starting position of the string Try to match the pattern, and return None if the starting position is not matched successfully.
re.search(pattern, string): Search for pattern in the string. If the match is successful, return the first matching object, otherwise return None.
re.findall(pattern, string): Returns a list of all content in the string that matches the pattern.
re.finditer(pattern, string): Returns an iterator of all contents in the string that match the pattern.
re.sub(pattern, repl, string, count=0): Use repl to replace all or part of the parts in string that match pattern. The count parameter is used to specify the number of replacements.
re.split(pattern, string, maxsplit=0, flags=0): Split the string into multiple parts according to the matching splitting rules and return a list.
re.escape(string): Add the escape character "\" before the special characters in the string to turn them into ordinary characters.
re.purge(): Clear the regular expression compilation cache to avoid unnecessary compilation.
re.escape(string): Add the escape character "\" before the special characters in the string to turn them into ordinary characters.
These methods provide various regular expression operations, including pattern matching, search, replacement, splitting, etc. You can choose the appropriate method to operate according to specific needs.
Python’s re module is one of the core modules for regular expression operations. Regular expressions are a powerful tool for matching, searching, and replacing text. Regular expressions use special syntax to represent patterns. The following are some common regular expression syntax:
. : Matches any character (except newline).
^ : Matches the beginning of the string.
$ : Matches the end of the string.
[...] : Represents a set of characters from which a character can be selected. For example, [A-Za-z] matches any of the letters A through Z or a through z.
[^...] : Indicates characters not included in the set. For example, [^A-Za-z] matches any character except the letters A to Z or a to z.
[a-z] : Matches any lowercase letters.
[A-Z] : Matches any uppercase letters.
[0-9]: Matches any number.
\d: Matches any decimal digit, equivalent to [0-9].
\D: Matches any non-numeric characters, equivalent to [^0-9].
\s: Matches any whitespace character, equivalent to [\t\n\r\f].
\S : Matches any non-whitespace character.
\w : Matches any alphanumeric character, equivalent to [a-zA-Z0-9_].
\W : Matches any non-alphanumeric character.
\b : Matches any word boundary (between a word and whitespace). For example, 'w\b' will not match the 'w' in 'works', but will match the preceding 'w' in 'world'. 'WV\b' also does not match 'WV' in 'WVREPUBLIC', but will match 'WV' in 'WEST VIRGINIA'. Note that this has nothing to do with whether the following character is a letter or number.
\B : Matches any non-word boundary (between a word and non-whitespace). For example, 'w\B' will match the 'w' in 'world', but not the 'w' in 'what'. 'WV\B' will also not match 'WV' in 'WVREPUBLIC', but will match 'WV' in 'WEST VIRGINIA'. Note that this has nothing to do with whether the previous character is a letter or number.
|: Indicates selection, for example, a|b|c matches "a", "b" or "
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