same_columns error

[nagdawi]

# We already established that all tables have the same number of columns, but are they the same columns?
# This next piece of code loops over all given tables and compares each of them to all others.

for i in range(0,len(dataset)):
    if i != len(dataset)-1:
        same_columns = dataset[i].columns == dataset[i+1].columns
        
        if False in same_columns:
            print(i)
            break

same_columns

where is the right place of last line as it shows error currently?