python遍历字典dict

python3中：

>>> d = {'x': 1, 'y': 2, 'z': 3}

1. 遍历keys

>>> for k in d:
...     print(k)
...     print(d[key])
... 
y
3
x
3
z
3

2. 遍历keys，values

>>> for k,v in d.items():
...     print(k)
...     print(v)
... 
y
2
x
1
z
3

3. 遍历keys

>>> for k in d.keys():
...     print(k)
...     print(d[k])
... 
y
2
x
1
z
3

4. 遍历values

>>> for v in d.values():
...     print(v)
... 
2
1
3

python2中稍有区别，items()、keys()、values()换成iteritems()、iterkeys()、itervalues()