Identity Matrix

Problem

Build the n x n identity matrix I, where I[i][j] = 1 if i == j and 0 otherwise.

If n is 0, return an empty list.

Hint

Nested comprehension with a conditional expression.

case 1

in: [1]

expected: [[1]]

case 2

in: [2]

expected: [[1,0],[0,1]]

case 3

in: [3]

expected: [[1,0,0],[0,1,0],[0,0,1]]

case 4

in: [0]

expected: []

Starter codePython

def identity_matrix(n):
    # Your code here
    pass

4 test cases · run your code against them in the editor