python reverse()方法

发布时间:2019-09-15 10:17:04编辑:auto阅读(13384)

    Python中 reverse()是列表的内置方法,无参数,无返回值,reverse()会改变列表(原地反转),因此无需返回值。字典元组、字符串不具有reverse()方法,如果调用将会返回一个异常.

    >>> help(list.reverse)
    Help on method_descriptor:

    reverse(...)
        L.reverse() --
    reverse *IN PLACE*


    >>> l=[1,2,3,4,5]
    >>> l.reverse()
    >>> l
    [5, 4, 3, 2, 1]

    >>> t=(2,3,4,5,6)
    >>> t.reverse()#报错

    AttributeError: 'tuple' object has no attribute 'reverse'

    >>> s='python'
    >>> s.reverse()#报错

    AttributeError: 'str' object has no attribute 'reverse'

    >>> d={'a':1,'b':2}
    >>> d.reverse()#报错

    AttributeError: 'dict' object has no attribute 'reverse'

    (完)

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