189_rotate-array.py

class Solution:
    def rotate(self, nums, k):
        """
        :type nums: List[int]
        :type k: int
        :rtype: void Do not return anything, modify nums in-place instead.
        """
        k = k % len(nums)
        nums[:] = nums[-k:] + nums[:-k]


Solution().rotate([1, 2], 1)