import re
pattern = re.compile(r'\baaa_')
my_list = [['aaa_house', 'aaa_car', 'aaa_table'], ['aaa_love', 'aaa_hate', 'aaa_life']]
print([[pattern.sub('', i) for i in y] for y in my_list])
aW1wb3J0IHJlCgpwYXR0ZXJuID0gcmUuY29tcGlsZShyJ1xiYWFhXycpCm15X2xpc3QgPSBbWydhYWFfaG91c2UnLCAnYWFhX2NhcicsICdhYWFfdGFibGUnXSwgWydhYWFfbG92ZScsICdhYWFfaGF0ZScsICdhYWFfbGlmZSddXQpwcmludChbW3BhdHRlcm4uc3ViKCcnLCBpKSBmb3IgaSBpbiB5XSBmb3IgeSBpbiBteV9saXN0XSkKCg==