Python enumerate()

wanmin444

　　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[0]), (1, seq[1]), (2, seq[2]), ...
  
• 
  
• |
  
• 
  
• |  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