How to rotate a matrix by one element anti clockwise- using python

# Function to rotate a matrix anticlockwise
# Modified code from https://www.geeksforgeeks.org/rotate-matrix-elements/
# Question :
# https://stackoverflow.com/questions/37839572/how-to-rotate-a-matrix-by-one-element-anti-clockwise-n-times-using-c-or-in-pyt
# By Devansh Sehgal
def rotMatrixAntiClock(mat):

    if not len(mat):
        return

    """
        top : starting row index
        bottom : ending row index
        left : starting column index
        right : ending column index
    """

    top = 0
    bottom = len(mat)-1

    left = 0
    right = len(mat[0])-1

    while left < right and top < bottom:

        # Store the first element of next row,
        # this element will replace first element of
        # current row
        prev = mat[top+1][right]
        # Move elements of top row one step left
        for i in range(right,left-1,-1):
            curr = mat[top][i]
            mat[top][i] = prev
            prev = curr

        top += 1

        # Move elements of leftmost column one step downwards
        for i in range(top, bottom+1):
            curr = mat[i][left]
            mat[i][left] = prev
            prev = curr

        left += 1

        # Move elements of bottom row one step right
        for i in range(left,right+1):
            curr = mat[bottom][i]
            mat[bottom][i] = prev
            prev = curr

        bottom -= 1

        # Move elements of rightmost column one step upwards
        for i in range(bottom, top-1, -1):
            curr = mat[i][right]
            mat[i][right] = prev
            prev = curr

        right -= 1

    return mat