考虑一下:
the_data = ['a','b','c']
使用枚举此循环可以写为:
for index,item in enumerate(the_data):
# index = 1 , item = 'a'
如果the_data = { 'john':'football','mary':'snooker','dhruv':'hockey'}
循环,在循环中分配键值对:
for name,sport in the_data.iteritems():
#name -> john,sport-> football
使用枚举时,数据成为循环中的元组,因此在循环声明后需要一个额外的赋值行:
#can assignment of name & sport happen within the `for-in` line itself ?
for index,name_sport_tuple in enumerate(the_data.iteritems()):
name,sport = name_sport_tuple # Can this line somehow be avoided ?
#index-> 1,name-> john, sport -> football
答案 0 :(得分:13)
使用此:
for index, (name, sport) in enumerate(the_data.iteritems()):
pass
这相当于:
>>> a, (b, c) = [1, (2, 3)]
>>> a, b, c
(1, 2, 3)
这通常与zip
和enumerate
组合一起使用:
for i, (a, b) in enumerate(zip(seq1, seq2)):
pass