4.2.4 Regular Expression Objects

Compiled regular expression objects support the following methods and attributes:

match( string[, pos[, endpos]])

If zero or more characters at the beginning of string match this regular expression, return a corresponding MatchObject instance. Return None if the string does not match the pattern; note that this is different from a zero-length match.

Note: If you want to locate a match anywhere in string, use search() instead.

The optional second parameter pos gives an index in the string where the search is to start; it defaults to 0. This is not completely equivalent to slicing the string; the '^' pattern character matches at the real beginning of the string and at positions just after a newline, but not necessarily at the index where the search is to start.

The optional parameter endpos limits how far the string will be searched; it will be as if the string is endpos characters long, so only the characters from pos to endpos - 1 will be searched for a match. If endpos is less than pos, no match will be found, otherwise, if rx is a compiled regular expression object, rx.match(string, 0, 50) is equivalent to rx.match(string[:50], 0).

search( string[, pos[, endpos]])

Scan through string looking for a location where this regular expression produces a match, and return a corresponding MatchObject instance. Return None if no position in the string matches the pattern; note that this is different from finding a zero-length match at some point in the string.

The optional pos and endpos parameters have the same meaning as for the match() method.

split( string[, maxsplit = 0])

Identical to the split() function, using the compiled pattern.

findall( string[, pos[, endpos]])

Identical to the findall() function, using the compiled pattern.

finditer( string[, pos[, endpos]])

Identical to the finditer() function, using the compiled pattern.

sub( repl, string[, count = 0])

Identical to the sub() function, using the compiled pattern.

subn( repl, string[, count = 0])

Identical to the subn() function, using the compiled pattern.

flags

The flags argument used when the RE object was compiled, or 0 if no flags were provided.

groupindex

A dictionary mapping any symbolic group names defined by (?P<id>) to group numbers. The dictionary is empty if no symbolic groups were used in the pattern.

pattern

The pattern string from which the RE object was compiled.