Python3基础 dict __len__ 统计键值对的数量

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• ???????Python : 3.7.3
• ?????????OS : Ubuntu 18.04.2 LTS
• ????????IDE : pycharm-community-2019.1.3
• ??????Conda : 4.7.5
• ???typesetting : Markdown

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code

coder@ubuntu:~$ source activate py37
(py37) coder@ubuntu:~$ ipython
Python 3.7.3 (default, Mar 27 2019, 22:11:17) 
Type 'copyright', 'credits' or 'license' for more information
IPython 7.5.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: my_dict = { 
   ...:     "子": "鼠", 
   ...:     "丑": "牛", 
   ...:     "寅": "虎", 
   ...:     "卯": "兔", 
   ...:     "辰": "龙", 
   ...:     "巳": "蛇", 
   ...:     "午": "马", 
   ...:     "未": "羊", 
   ...:     "申": "猴", 
   ...:     "酉": "鸡", 
   ...:     "戌": "狗", 
   ...:     "亥": "猪" 
   ...: }                                                                       

In [2]: my_dict.__len__()                                                       
Out[2]: 12

In [3]: exit                                                                    
(py37) coder@ubuntu:~$ conda deactivate
coder@ubuntu:~$ 

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source_code

def __len__(self, *args, **kwargs): # real signature unknown
    """ Return len(self). """
    pass

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resource

• [文档 - English] docs.python.org/3
• [文档 - 中文] docs.python.org/zh-cn/3
• [规范] www.python.org/dev/peps/pep-0008
• [规范] zh-google-styleguide.readthedocs.io/en/latest/google-python-styleguide/python_language_rules
• [源码] www.python.org/downloads/source
• [ PEP ] www.python.org/dev/peps
• [平台] www.cnblogs.com
• [平台] gitee.com

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Python具有开源、跨平台、解释型、交互式等特性，值得学习。
Python的设计哲学：优雅，明确，简单。提倡用一种方法，最好是只有一种方法来做一件事。
代码的书写要遵守规范，这样有助于沟通和理解。
每种语言都有独特的思想，初学者需要转变思维、踏实践行、坚持积累。

Python3基础 dict __len__ 统计键值对的数量

原文：https://www.cnblogs.com/xingchuxin/p/11144131.html