Python 3 - Second Edition

28    Regular Expressions

The re module of the standard library provides extensive options for using regular expressions. In a regular expression, a text pattern is described by a special syntax, which can then be applied to different texts or text fragments. Basically, there are two major areas of use for regular expressions:

• Matching checks whether a text section matches the regular expression pattern. For example, a test that checks whether an entered email address is syntactically valid is performing matching.

• The second possible use of regular expressions is searching, which searches for text fragments within a larger text that match a regular expression.

Searching is a discipline in its own right; this behavior can’t be efficiently implemented ...