##
4.2.4 Regular Expression Objects

Compiled regular expression objects support the following methods and attributes:

`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.

`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)`.

`split`(string[, maxsplit`= 0`])
  Identical to the `split()` function, using the compiled pattern.

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

`finditer`(string)
  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.