import os
import re

for i in os.listdir("."):
    if i.endswith(".mkv"):
        regex = re.search("\[(?P<group>.*?)\] (?P<anime>.+?) - (?P<nc>[A-z]+|\d+)? ?(?P<episode>\d+)?", i)
        if regex is None:
            continue
        if regex.group("episode") is None:
            os.rename(i, regex.group("anime") + " - " + regex.group("episode").lstrip("0") + ".mkv")
        else:
            os.rename(i, regex.group("anime") + " - " + regex.group("nc") + " " + regex.group("episode").lstrip("0") + ".mkv")