identity_matrix

def is_identity_matrix(matrix):
    """ 
    Takes a square matrix as input and returns 
    True if the Matrix is an identity matrix,
    False otherwise
    """
    # check if the matrix is square
    for each in matrix:                 
        if len(each) != len(matrix):
            return False
    
    row = 0
    # iterate through the rows
    while row < len(matrix):
        col = 0
        # iterate through the columns
        while col < len(matrix):
            # check if the entry at the diagonal positons is 1
            if row == col:
                if matrix[row][col] != 1:
                    return False
            # check if all other entries are 0
            else:
                if matrix[row][col] != 0:
                    return False
            col = col + 1
        row = row + 1
    return True