The rstrip Method in Python: Removing Characters from the Right
Returns a copy of the specified string with specified characters removed from the end (right r — right).
rstrip([chars])
chars=None-- a string of characters to remove. If not specified, whitespace characters are removed. This is not a prefix or suffix, but a list of characters to remove.
'abca'.rstrip('ac') # 'ab'
The method behaves like lstrip, but it removes characters on the right.