class Solution(object):
    def transpose(self, A):
        """
        :type A: List[List[int]]
        :rtype: List[List[int]]
        """
        if len(A)==0:
            return A
        B=[]
        for i in range(len(A[0])):
            col=[line[i] for line in A]
            B.append(col)
        return B