轉(zhuǎn)https://www.cnblogs.com/ducklu/p/8943903.html

1.遍歷key值

            1 >>> d = {'Python':'astonishing', 'C++':'complicated', 'Java':'versatile'}
2 >>> for key in d:
3 ...     print(key + ':' + d[key])
4 ...
5 Python:astonishing
6 C++:complicated
7 Java:versatile
          

同理，可把下列代碼的d改為d.keys()

notice:python2除了上述兩種方法外，還可以寫(xiě)為d.iterkeys()

?

2.遍歷value值

            1 >>> for value in d:
2 ...     print(value)
3 ...
4 Python
5 C++
6 Java
          

同理，可把下列代碼的d改為d.values()

notice:python2除了上述兩種方法外，還可以寫(xiě)為d.itervalues()

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3.遍歷字典

             1 >>> for kv in d.items():
 2 ...     print(kv)
 3 ...
 4 ('Python', 'astonishing')
 5 ('C++', 'complicated')
 6 ('Java', 'versatile')
 7 >>> for k, v in d.items():#開(kāi)始偷懶，縮寫(xiě)k, v
 8 ...     print(k + ':' + v)
 9 ...
10 Python:astonishing
11 C++:complicated
12 Java:versatile
          

其實(shí)還有一種方法，用到了zip(元素對(duì))使得我們可以像c/c++等語(yǔ)言一樣循環(huán)兩個(gè)變量

            1 >>> for k, v in zip(d.keys(), d.values()):
2 ...     print(k + ':' + v)
3 ...
4 Python:astonishing
5 C++:complicated
6 Java:versatile
          

?關(guān)于zip的用法，詳見(jiàn)python cookbook:https://python3-cookbook.readthedocs.io/zh_CN/latest/c04/p11_iterate_over_multiple_sequences_simultaneously.html

不忘初心，方得始終