ch7 ex6 circularly identical

def circularly_identical(list1, list2):

    # doubling list
    list3 = list1 * 2

    # traversal in twice of list1
    for x in range(0, len(list1)):
        z = 0

        # check if list2 == list1 curcularly
        for y in range(x, x + len(list1)):
            if list2[z]== list3[y]:
                z+= 1
            else:
                break

        # if all n elements are same circularly
        if z == len(list1):
            return True

    return False