Python NameError: Name 'xxx' Is Not Defined

puzzle = [[' 1', ' 2', ' 3', ' 4'], [' 5', ' 6', ' 7', ' 8'],[ ' 9', '10', '11', '12'], ['13', '14', '15', ' X']] def find_pos(alist, item): for i in alist: for j in r

Solution 1:

Just return the values from the function:

puzzle = [[' 1', ' 2', ' 3', ' 4'], [' 5', ' 6', ' 7', ' 8'],[ ' 9', '10', '11', '12'], ['13', '14', '15', ' X']]

def find_pos(alist, item):
    for i in alist:
        for j in range(4):
            if i[j] == item:
                row = alist.index(i)
                col = j
                return row, col

row, col = find_pos(puzzle,' X')

print(row)

Note that if the item isn't found, it will return None (because every function that doesn't return anything returns None by default), in which case the code will throw an error.