__file__ 变量是什么意思/做什么? [英] what does the __file__ variable mean/do?

问题描述

import os

A = os.path.join(os.path.dirname(__file__), '..')

B = os.path.dirname(os.path.realpath(__file__))

C = os.path.abspath(os.path.dirname(__file__))

我通常只是将它们与实际路径硬连线.但是这些语句在运行时确定路径是有原因的，我真的很想了解 os.path 模块，以便我可以开始使用它.

I usually just hard-wire these with the actual path. But there is a reason for these statements that determine path at runtime, and I would really like to understand the os.path module so that I can start using it.

推荐答案

当从 Python 中的文件加载模块时，__file__ 被设置为其路径.然后，您可以将其与其他函数一起使用以查找文件所在的目录.

When a module is loaded from a file in Python, __file__ is set to its path. You can then use that with other functions to find the directory that the file is located in.

一次举一个例子:

A = os.path.join(os.path.dirname(__file__), '..')
# A is the parent directory of the directory where program resides.

B = os.path.dirname(os.path.realpath(__file__))
# B is the canonicalised (?) directory where the program resides.

C = os.path.abspath(os.path.dirname(__file__))
# C is the absolute path of the directory where the program resides.

您可以在此处查看从这些返回的各种值:

You can see the various values returned from these here:

import os
print(__file__)
print(os.path.join(os.path.dirname(__file__), '..'))
print(os.path.dirname(os.path.realpath(__file__)))
print(os.path.abspath(os.path.dirname(__file__)))

并确保从不同的位置(例如 ./text.py、~/python/text.py 等)运行它，看看有什么不同

and make sure you run it from different locations (such as ./text.py, ~/python/text.py and so forth) to see what difference that makes.

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