不行, 你能正回答出段程序的出? - V2EX
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013231
V2EX    Python

不行, 你能正回答出段程序的出?

  •  
  •   013231 2012-09-13 20:34:55 +08:00 3635 次点击
    这是一个创建于 4777 天前的主题,其中的信息可能已经有所发展或是发生改变。
    x = [lambda: x for x in range(10)]
    print x[0]()
    x = (lambda: x for x in range(10))
    print x.next()()
    print [lambda: x for x in range(10)][0]()
    5 条回复    1970-01-01 08:00:00 +08:00
    likai
        1
    likai  
       2012-09-13 21:01:11 +08:00
    这和头脑风暴上的一段代码何其相似
    fanzeyi
        2
    fanzeyi  
       2012-09-13 21:05:45 +08:00
    果不其然的做错了=.=

    答案太丑就不贴了..

    俺来解析下

    https://gist.github.com/3714157

    # 不直接贴出来了 =.=
    pyKun
        3
    pyKun  
       2012-10-10 18:37:42 +08:00
    x = [lambda: x for x in range(10)]
    这个运行看到结果了,但不明白。。。

    @fanzeyi 看你的解析也没明白。。。
    首先是个list是肯定的,你解析里的的“lambda x”是什么意思?
    013231
        4
    013231  
    OP
       2012-10-10 21:23:10 +08:00   1
    @pyKun
    x = [lambda: x for x in range(10)]
    x[0]就是lambda: x
    lambda表式中的x引用的是哪量呢? 函作用域内找不到, 就到外作用域即全局作用域去找, 然後找到了.
    也就是x[0]()返回的是x自身.
    pyKun
        5
    pyKun  
       2012-10-10 22:52:39 +08:00
    @013231 嗯。。明白了。。。
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