bre.py 文件源码

def compile_replace(pattern, repl, flags=0):
    """Construct a method that can be used as a replace method for `sub`, `subn`, etc."""

    call = None
    if pattern is not None and isinstance(pattern, RE_TYPE):
        if isinstance(repl, (compat.string_type, compat.binary_type)):
            repl = ReplaceTemplate(pattern, repl, bool(flags & FORMAT))
            call = Replace(
                functools.partial(_apply_replace_backrefs, repl=repl), repl.use_format, repl.pattern_hash
            )
        elif isinstance(repl, Replace):
            if flags:
                raise ValueError("Cannot process flags argument with a compiled pattern!")
            if repl.pattern_hash != hash(pattern):
                raise ValueError("Pattern hash doesn't match hash in compiled replace!")
            call = repl
        elif isinstance(repl, ReplaceTemplate):
            if flags:
                raise ValueError("Cannot process flags argument with a ReplaceTemplate!")
            call = Replace(
                functools.partial(_apply_replace_backrefs, repl=repl), repl.use_format, repl.pattern_hash
            )
        else:
            raise TypeError("Not a valid type!")
    else:
        raise TypeError("Pattern must be a compiled regular expression!")
    return call


# Convenience methods like re has, but slower due to overhead on each call.
# It is recommended to use compile_search and compile_replace