Python3基礎 getattr 獲取對象的指定屬性值

 

•        Python : 3.7.0
•          OS : Ubuntu 18.04.1 LTS
•         IDE : PyCharm 2018.2.4
•       Conda : 4.5.11
•    typesetting : Markdown

 

code

coder@Ubuntu:~$ source activate py37
(py37) coder@Ubuntu:~$ ipython
Python 3.7.0 (default, Jun 28 2018, 13:15:42) 
Type 'copyright', 'credits' or 'license' for more information
IPython 6.5.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: class MyClass:
   ...:     # 類屬性
   ...:     num = 0
   ...: 
   ...: 

In [2]: getattr(MyClass,'num')  # 屬性的名字是字符串
Out[2]: 0

In [3]: # 還能夠進行加說明，防止拋異常

In [4]: introduction = '你所訪問的屬性不存在'

In [5]: print(getattr(MyClass, 'name', introduction))
你所訪問的屬性不存在

In [6]: # 若是你訪問的屬性不存在，會拋異常

In [7]: getattr(MyClass, 'name')
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-7-4454b72514b0> in <module>()
----> 1 getattr(MyClass, 'name')

AttributeError: type object 'MyClass' has no attribute 'name'

In [8]: exit
(py37) coder@Ubuntu:~$ source deactivate
coder@Ubuntu:~$

 

resource

• [文檔] docs.python.org/3
• [規範] www.python.org/dev/peps/pep-0008
• [規範] zh-google-styleguide.readthedocs.io/en/latest/google-python-styleguide/python_language_rules
• [源碼] www.python.org/downloads/source
• [ PEP ] www.python.org/dev/peps
• [平臺] www.cnblogs.com
• [平臺] gitee.com

 

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