wanmin444 发表于 2018-8-11 11:27:46

Python enumerate()

  在python中使用enumerate() function.
  在对列表遍历的时候.我是使用 for 进行遍历,今天发现enumerate 可以在同时需要index和value的时候用
  


[*]>>> name
[*]['ca', 'tom', 'lili', 'sunwukong']
[*]>>> for i in range(len(name)):
[*]...   print i,name
[*]...
[*]0 ca
[*]1 tom
[*]2 lili
[*]3 sunwukong
  

  使用enumerate() function 可以更效率,更方便一些
  


[*]>>> for i,eachname in enumerate(name):
[*]...   print "%d %s" %(i,eachname)
[*]...
[*]0 ca
[*]1 tom
[*]2 lili
[*]3 sunwukong
  


以下摘在python help  


[*]class enumerate(object)
[*]
[*] |enumerate(iterable[, start]) -> iterator for index, value of iterable
[*]
[*] |
[*]
[*] |Return an enumerate object.iterable must be another object that supports
[*]
[*] |iteration.The enumerate object yields pairs containing a count (from
[*]
[*] |start, which defaults to zero) and a value yielded by the iterable argument.
[*]
[*] |enumerate is useful for obtaining an indexed list:
[*]
[*] |      (0, seq), (1, seq), (2, seq), ...
[*]
[*] |
[*]
[*] |Methods defined here:
[*]
[*] |
[*]
[*] |__getattribute__(...)
[*]
[*] |      x.__getattribute__('name') <==> x.name
[*]
[*] |
[*]
[*] |__iter__(...)
[*]
[*] |      x.__iter__() <==> iter(x)
[*]
[*] |
[*]
[*] |next(...)
[*]
[*] |      x.next() -> the next value, or raise StopIteration
[*]
[*] |
[*]
[*] |----------------------------------------------------------------------
[*]
[*] |Data and other attributes defined here:
[*]
[*] |
[*]
[*] |__new__ = <built-in method __new__ of type object>
[*]
[*] |      T.__new__(S, ...) -> a new object with type S, a subtype of T
  
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