Python 类动态属性访问

2022-01-13 00:00:00 python eval dynamic attributes

问题描述

我想通过一个带有名字的字符串来访问一个类属性.

I want to access a class attribute by a string with its name.

类似:

class a:
    b=[]

c='b'
eval('a.'+c+'=1')

但这在 Python 中不起作用.我该怎么做?

But that doesn't work in Python. How can I do this?

解决方案

使用<代码>setattr:

In [1]: class a:
   ...:     b = []
   ...:     

In [2]: setattr(a, 'b', 1)

In [3]: a.b
Out[3]: 1

反向使用 getattr:

In [4]: getattr(a, 'b')
Out[4]: 1

In [5]: getattr(a, 'x', 'default')
Out[5]: 'default'

不过，我非常怀疑有更好的方法来实现您的目标.您是否尝试过使用字典而不是类?

I very much suspect, though, that there is a better way to achieve whatever your goal is. Have you tried using a dictionary instead of a class?

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