关于列表推导式

轻红

在第12讲里面小甲鱼老师提到了列表推导式，然后课后作业是
先IDLE获取以下列表的结果，然后把列表推导式还原出来
>>> list1 = [(x, y) for x in range(10) for y in range(10) if x%2==0 if y%2!=0]

在IDLE中打印list1的结果是
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9), (6, 1), (6, 3), (6, 5), (6, 7), (6, 9), (8, 1), (8, 3), (8, 5), (8, 7), (8, 9)]

然后小甲鱼老师的列表推导式还原结果是：
list1 = []
for x in ragne(10):
    for y in range(10):
        if x%2 == 0:
            if y%2 != 0:
                list1.append((x, y))

但是用这个推导式去打印print(list1)的话，得到的结果不止是[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9), (6, 1), (6, 3), (6, 5), (6, 7), (6, 9), (8, 1), (8, 3), (8, 5), (8, 7), (8, 9)]

而是：
[(0, 1)]
[(0, 1), (0, 3)]
[(0, 1), (0, 3), (0, 5)]
[(0, 1), (0, 3), (0, 5), (0, 7)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9), (6, 1)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9), (6, 1), (6, 3)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9), (6, 1), (6, 3), (6, 5)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9), (6, 1), (6, 3), (6, 5), (6, 7)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9), (6, 1), (6, 3), (6, 5), (6, 7), (6, 9)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9), (6, 1), (6, 3), (6, 5), (6, 7), (6, 9), (8, 1)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9), (6, 1), (6, 3), (6, 5), (6, 7), (6, 9), (8, 1), (8, 3)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9), (6, 1), (6, 3), (6, 5), (6, 7), (6, 9), (8, 1), (8, 3), (8, 5)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9), (6, 1), (6, 3), (6, 5), (6, 7), (6, 9), (8, 1), (8, 3), (8, 5), (8, 7)]
[(0, 1), (0, 3), (0, 5), (0, 7), (0, 9), (2, 1), (2, 3), (2, 5), (2, 7), (2, 9), (4, 1), (4, 3), (4, 5), (4, 7), (4, 9), (6, 1), (6, 3), (6, 5), (6, 7), (6, 9), (8, 1), (8, 3), (8, 5), (8, 7), (8, 9)]

想知道这是为什么呢？为什么两个列表不是同样的条件么为什么结果是不一样的呢？
QWQ  跪求各位大神解释一下~

wei_Y

注意缩进。

轻红

wei_Y 发表于 2015-8-10 20:59
注意缩进。

0 0 是因为缩进的问题么。。
是哪个缩进呢- -
迟钝的人表示没有看出来OTZ

wei_Y

轻红 发表于 2015-8-10 21:01
0 0 是因为缩进的问题么。。
是哪个缩进呢- -
迟钝的人表示没有看出来OTZ

你是不是把打印放在和list.append同级了。放在最外层就会看到一样的结果了。

轻红

wei_Y 发表于 2015-8-10 21:05
你是不是把打印放在和list.append同级了。放在最外层就会看到一样的结果了。

啊 0 0   的确放最外层就是一样的结果了！
谢谢版主解答QWQ
可是为什么放在里面和放在外面是不一样的呢？

～风介～

轻红 发表于 2015-8-10 21:29
啊 0 0   的确放最外层就是一样的结果了！
谢谢版主解答QWQ
可是为什么放在里面和放在外面是不一样的呢 ...

可是为什么放在里面和放在外面要是一样的呢？

faye_vip

轻红 发表于 2015-8-10 21:29
啊 0 0   的确放最外层就是一样的结果了！
谢谢版主解答QWQ
可是为什么放在里面和放在外面是不一样的呢 ...

一个在循环里一个在循环外

蓝色披风

if语句你可以这么写：
if （x%2 == 0） and (y%2 != 0):
所以还是缩进的问题，你那样写相当于就重复了之前的操作，打印出来的就多了