Python - Regular Expression (called REs, or regexes, or regex patterns)
Table of Contents
About
Regular expression in Python
The regexp in Python have matching operations similar to those found in Perl.
Articles Related
Backslash
- the backslash character ('\') indicate special forms or allow special characters
- for example, to match a literal backslash, one might have to write '\\\\' as the pattern string, because the regular expression must be \\, and each backslash must be expressed as
inside a regular Python string literal. - 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.
Tester
Example
Web Log Parsing
Log - Apache Common Log Format
'^(\S+) (\S+) (\S+) \[([\w:/]+\s[+\-]\d{4})\] "(\S+) (\S+)\s*(\S*)" (\d{3}) (\S+)'
127.0.0.1 - - [24/Jul/1973:08:32:01 -0400] "GET /images/gerardnico.gif HTTP/1.0" 200 2564