为什么循环的代码顺序不一样运行出来的不一样(关键词-5S)

Question

x = ["Mon", "Tues", "Wed", "Thur", "Fri","Sat","Sun"]
y = [20, 40, 35, 55, 42, 80, 50]
z=[1,2,3,4,5,6,7]
for x1, y1,z1 in zip(x,y,z):
    print(x1,y1,z1)
for x in zip(x,y,z):
    print(x)

输出的结果是正确的

Mon 20 1
Tues 40 2
Wed 35 3
Thur 55 4
Fri 42 5
Sat 80 6
Sun 50 7
('Mon', 20, 1)
('Tues', 40, 2)
('Wed', 35, 3)
('Thur', 55, 4)
('Fri', 42, 5)
('Sat', 80, 6)
('Sun', 50, 7)

然而

x = ["Mon", "Tues", "Wed", "Thur", "Fri","Sat","Sun"]
y = [20, 40, 35, 55, 42, 80, 50]
z=[1,2,3,4,5,6,7]
for x in zip(x,y,z):
    print(x)
for x1, y1,z1 in zip(x,y,z):
    print(x1,y1,z1)

输出的却是

('Mon', 20, 1)
('Tues', 40, 2)
('Wed', 35, 3)
('Thur', 55, 4)
('Fri', 42, 5)
('Sat', 80, 6)
('Sun', 50, 7)
Sun 20 1
50 40 2
7 35 3

这是为啥？

Answer 1

1. x变量值被第一个循环改变了，第一个for x in zip(x,y,z):循环完成x=('Sun', 50, 7)
2. for x1, y1,z1 in zip(x,y,z):循环时，x=('Sun', 50, 7) y = [20, 40, 35, 55, 42, 80, 50] z=[1,2,3,4,5,6,7]
3. 所以输出不是你想要的
4. 修改第一个循环变量 for a in zip(x,y,z):