import os

path = "C:\Program Files\Steam\steamapps\mupet0000\Counter-Strike Source\cstrike\maps"

maps = os.listdir(path)
ggmaps = []
for map in maps:
    if map.startswith("gg_") and map.endswith(".bsp"):
        ggmaps.append(map.replace(".bsp", ""))
maplist = open("C:\maplist.txt", "w")
for map in ggmaps:
    maplist.write(map+"\n")
maplist.close()