python regular expressions.pdf 正则表达式

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PYTHON REGULAR EXPRESSIONS

PYTHON REGULAR EXPRESSIONS

A regular expression is a special sequence of characters that helps you match or find other strings

or sets of strings, using a specialized syntax held in a pattern. Regular expressions are widely used

in UNIX world.

The module re provides full support for Perl-like regular expressions in Python. The re module

This function attempts to match RE pattern to string with optional flags.

Here is the syntax for this function −

re.match(pattern, string, flags=0)

Here is the description of the parameters:

Parameter Description

pattern This is the regular expression to be matched.

string This is the string, which would be searched to match the pattern at

the beginning of string.

flags You can specify different flags using bitwise OR | . These are

Example