Generating circular shifts / reduced Latin Squares in Python

Question

Was just wondering what\'s the most efficient way of generating all the circular shifts of a list in Python. In either direction. For example, given a list [1, 2, 3, 4

Answer 1

You can use collections.deque:

from collections import deque

g = deque([1, 2, 3, 4])

for i in range(len(g)):
    print list(g) #or do anything with permutation
    g.rotate(1) #for right rotation
    #or g.rotate(-1) for left rotation

It prints:

 [1, 2, 3, 4]
 [4, 1, 2, 3]
 [3, 4, 1, 2]
 [2, 3, 4, 1]

To change it for left rotation just replace g.rotate(1) with g.rotate(-1).