The re module has the following flags (amongst others):

re.X == re.VERBOSE
re.S == re.DOTALL

The short forms of both these flags are clearly taken from Perl, but
they don't seem necessary for Python and are confusing since all the
other short names start with the same letter as the long name, e.g.,
re.I == re.IGNORECASE and re.M == re.MULTILINE.

Why not add re.V for re.VERBOSE and re.D for re.DOTALL and kill re.X and
re.S and say a final farewell to Perl?

Please keep them.  They correspond to the (?x) and (?s) syntax that is
supported inside the regex.

Perl compatibility is a feature, not a bug for the re module.