def transpose(matrix):
n=0
while n < (len(matrix)):
li = []
for sets in matrix:
li.append(sets[0])
n += 1
print(len(matrix))
return li
transpose([[1,2,3],[4,5,6],[7,8,9]])
目前返回[1,4,7]通缉结果[[1,4,7],[2,5,8],[3,6,9]]