我如何通过__dict__在python中分配一个新的类属性? [英] How can I assign a new class attribute via __dict__ in python?
本文介绍了我如何通过__dict__在python中分配一个新的类属性?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想通过字符串对象分配类属性 - 但是如何?
示例:
class test(object):
pass
a = test()
test.value = 5
a.value
# - > 5
test .__ dict __ ['value']
# - > 5
#BUT:
attr_name ='next_value'
test .__ dict __ [attr_name] = 10
# 'dictproxy'对象不支持项分配
解决方案
一个内置函数为:
setattr(test,attr_name,10)
/ pre>
参考: http ://docs.python.org/library/functions.html#setattr
示例:
>>> class a(object):pass
>>> a .__ dict __ ['wut'] = 4
回溯(最近最后一次调用):
在< module>中第1行的文件< stdin&
TypeError:'dictproxy'对象不支持项分配
>>> setattr(a,'wut',7)
>>>> a.wut
7
I want to assign a class attribute via a string object - but how?
Example:
class test(object): pass a = test() test.value = 5 a.value # -> 5 test.__dict__['value'] # -> 5 # BUT: attr_name = 'next_value' test.__dict__[attr_name] = 10 # -> 'dictproxy' object does not support item assignment
解决方案There is a builtin function for this:
setattr(test, attr_name, 10)
Reference: http://docs.python.org/library/functions.html#setattr
Example:
>>> class a(object): pass >>> a.__dict__['wut'] = 4 Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'dictproxy' object does not support item assignment >>> setattr(a, 'wut', 7) >>> a.wut 7
这篇关于我如何通过__dict__在python中分配一个新的类属性?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文