Based on the example provided in this answer, how can I create a function from:

from collections import Counter
s =  ['0', '0', '2', '1', '1', '0', '0', '0']
try:print(next(t[0] for t in Counter(s).most_common(2) if t[0] != '0'))
except StopIteration:print('0')

This code doesn't work:

def most_common_number(s):try:return next(t[0] for t in Counter(s).most_common(2) if t[0] != '0')except StopIteration:'0'

If it is possible to get the same results without try-except please let me know

You need to return from the except block.

def most_common_number(s):try:return next(t[0] for t in Counter(s).most_common(2) if t[0] != '0')except StopIteration:return '0'