pat : string or compiled regex

String can be a character sequence or regular expression.

New in version 0.20.0: pat also accepts a compiled regex.

repl : string or callable

Replacement string or a callable. The callable is passed the regex match object and must return a replacement string to be used. See re.sub().

New in version 0.20.0: repl also accepts a callable.

n : int, default -1 (all)

Number of replacements to make from start

case : boolean, default None

• If True, case sensitive (the default if pat is a string)
• Set to False for case insensitive
• Cannot be set if pat is a compiled regex

flags : int, default 0 (no flags)

• re module flags, e.g. re.IGNORECASE
• Cannot be set if pat is a compiled regex

regex : boolean, default True

• If True, assumes the passed-in pattern is a regular expression.
• If False, treats the pattern as a literal string
• Cannot be set to False if pat is a compiled regex or repl is a callable.

New in version 0.23.0.

replaced : Series/Index of objects

ValueError

• if regex is False and repl is a callable or pat is a compiled regex
• if pat is a compiled regex and case or flags is set