import re
strings = ['string01_','str_ing02_^','string03_@_', 'string04_1', 'string05_a_']
for item in strings:
clean_this = (re.sub(r'[_+!@#$?^]+$', '', item))
print (clean_this)
aW1wb3J0IHJlCnN0cmluZ3MgPSBbJ3N0cmluZzAxXycsJ3N0cl9pbmcwMl9eJywnc3RyaW5nMDNfQF8nLCAnc3RyaW5nMDRfMScsICdzdHJpbmcwNV9hXyddCgpmb3IgaXRlbSBpbiBzdHJpbmdzOgogIGNsZWFuX3RoaXMgPSAocmUuc3ViKHInW18rIUAjJD9eXSskJywgJycsIGl0ZW0pKQogIHByaW50IChjbGVhbl90aGlzKQ==