使用os.environ.setdefault是否安全? [英] Is it safe to use os.environ.setdefault?
问题描述
从我的ipython shell中,我在os.environ中看到了一个setdefault方法,但该方法没有记录. http://docs.python.org/library/os.html#os.environ .在其他地方有记录吗?
From my ipython shell, I see a method setdefault in os.environ but it is not documented. http://docs.python.org/library/os.html#os.environ. Is it documented somewhere else?
def setdefault(self, key, failobj=None):
if key not in self:
self[key] = failobj
return self[key]
我可以使用此功能或为这些行写一个包装器吗?
Can I use this function or write a wrapper for those lines?
推荐答案
os.environ
文档确实声明它是一个映射:
The os.environ
documentation does state it's a mapping:
表示字符串环境的映射对象.
A mapping object representing the string environment.
因此,它的行为符合python 映射文档,其中dict
是标准实现.
As such it behaves according to the python mapping documentation of which dict
is the standard implementation.
os.environ
的行为与标准dict一样,它具有所有相同的方法:
os.environ
therefor behaves just like the standard dict, it has all the same methods:
>>> import os
>>> len(os.environ)
36
>>> 'USER' in os.environ
True
>>> os.environ.fromkeys
<bound method classobj.fromkeys of <class os._Environ at 0x107096ce8>>
.setdefault
方法记录在与映射其余部分相同的页面上方法,您可以按原样使用它.
The .setdefault
method is documented on the same page as the rest of the mapping methods, and you can use it just fine as is.
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