在python中排序字典

Question

我有一个字典，我不断更新购买使用.update添加新的值和密钥，在循环中添加新密钥。我希望字典按照我添加它们的顺序打印出值。这可能吗？

Answer 1

您需要使用array而不是标准词典。它将保持秩序，但在其他方面就像一个正常的字典。

Answer 2

为此，您可以使用OrderedDict ，因为它会记住其内容的添加顺序。它是普通Python字典的子类，因此可以访问字典的所有功能。

示例：

In [1]: import collections

In [2]: normal_dict = {}

In [3]: normal_dict['key1'] = 1 # insert key1

In [4]: normal_dict['key2'] = 2 # insert key2

In [5]: normal_dict['key3'] = 3 # insert key3

In [6]: for k,v in normal_dict.items(): # print the dictionary
   ...:     print k,v
   ...:     
key3 3 # order of insertion is not maintained
key2 2
key1 1

In [7]: ordered_dict = collections.OrderedDict()

In [8]: ordered_dict['key1'] = 1 # insert key1

In [9]: ordered_dict['key2'] = 2 # insert key2

In [10]: ordered_dict['key3'] = 3 # insert key3

In [11]: for k,v in ordered_dict.items(): # print the dictionary
             print k,v
   ....:     
key1 1 # order of insertion is maintained
key2 2
key3 3