python遍历字典的四种方法

• 根据key值遍历

 1 >>> a
 2 {'a': '1', 'b': '2', 'c': '3'}
 3 >>> for key in a:
 4        print(key+':'+a[key])
 5  
 6 a:1
 7 b:2
 8 c:3
 9 >>> for key in a.keys():
10        print(key+':'+a[key])
11  
12 a:1
13 b:2
14 c:3

• 根据value遍历

>>> for value in a.values():
       print(value)
 
1
2
3

• 根据字典项遍历

1 >>> for kv in a.items():
2        print(kv)
3  
4 ('a', '1')
5 ('b', '2')
6 ('c', '3')

• 根据字典键值对遍历

 1 >>> for key,value in a.items():
 2        print(key+':'+value)
 3  
 4 a:1
 5 b:2
 6 c:3
 7 >>> for (key,value) in a.items():
 8        print(key+':'+value)
 9  
10 a:1
11 b:2
12 c:3