creating chessboard pattern with tables in python

Question

I need to make a chessboard pattern filled with 0 and 1 but it it doesn't have to be square table I need to get rows and columns from user

just an example:

1 0 1 0 1 0 1 0

0 1 0 1 0 1 0 1

1 0 1 0 1 0 1 0

0 1 0 1 0 1 0 1

1 0 1 0 1 0 1 0

I have the solution but I couldn't understand the last row of code ( table[i][j] = int(not table[i][j-1]) ) can we solve it using another method?

m = int(input("insert number of rows: "))
n = int(input("insert number of colomns: "))

table = list()

for i in range(0,m):

    if i%2 == 0 :
        table[i][0] = 1
    else:
        table[i][0] = 0

    for j in range(1,n):
        table[i][j] = int(not table[i][j-1])

print("print the table with chessboard pattern")
for i in range(0,m):
    for j in range(0,n):
        print(table[i][j],end='')
    print() 

Answer 1

You'll have a simpler time with a nested list comprehension that uses the x and y coordinates of the cell being generated and the modulo operator % to alternate between two values:

n_rows = n_cols = 5

table = [
    [((x + y + 1) % 2) for x in range(n_cols)]
    for y in range(n_rows)
]

for row in table:
    print(*row)

prints out

1 0 1 0 1
0 1 0 1 0
1 0 1 0 1
0 1 0 1 0
1 0 1 0 1

The list comprehension can be written out as nested for loops, too.

table = []

for y in range(n_rows):
    row = []
    for x in range(n_cols):
        row.append((x + y + 1) % 2)
    table.append(row)

Answer 2

You will have an error on line 6 because you can't assign a value to an index that doesn't exist..

You can do this instead:

m = int(input("insert number of rows: "))
n = int(input("insert number of colomns: "))

table = []

for i in range(m):
    if i%2==0:
        table.append([0+j%2 for j in range(n)])
    else:
        table.append([0+j%2 for j in range(1, n+1)])

You could also print it like this:

print("".join([str(row).replace('[', '').replace(']', '\n').replace(', ', ' ') for row in table]))