def find_common(self, l):
if len(l) == <NUM_LIT:1>:<EOL><INDENT>return l[<NUM_LIT:0>]<EOL><DEDENT>init = l[<NUM_LIT:0>]<EOL>for item in l[<NUM_LIT:1>:]:<EOL><INDENT>for i, (x, y) in enumerate(zip(init, item)):<EOL><INDENT>if x != y:<EOL><INDENT>init = "<STR_LIT>".join(init[:i])<EOL>break<EOL><DEDENT><DEDENT>if not init:<EOL><INDENT>return None<EOL><DEDENT><DEDENT>return init<EOL>
Find common parts in thelist items ex: 'ab' for ['abcd','abce','abf']
requires an ordered list