Making sure length of matrix row is all the same (python3)

Question

so I have this python 3 code to input a matrix:

matrix = []
lop=True
while lop:
    line = input()
    if not line:
        lop=False
    if matrix != []:
               


        

Answer 1

If you want match the first row length, Try this way,

Use len(matrix[0])

for row in matrix:
    if len(row) == len(matrix[0]):
        pass
    else:
       print('not same lenght')

Answer 2

Use the builtin len() function and a break statement.

matrix = []
lop =True
while lop:
    line = input('Enter your line: ')
    if not line:
        lop=False
    if matrix != []:
        if len(line.split()) != len(matrix[-1]):
            print("Not same length")
            break
    values = line.split()
    row = [int(value) for value in values]
    matrix.append(row)

This runs as:

bash-3.2$ python3 matrix.py
Enter your line: 1 2 3
Enter your line: 4 5 6
Enter your line: 7 8 9 0
Not same length
bash-3.2$