Python 从变量创建文件路径

Create file path from variables

提问by Thorsley

I am looking for some advice as to the best way to generate a file path using variables, currently my code looks similar to the following:

我正在寻找有关使用变量生成文件路径的最佳方法的一些建议，目前我的代码类似于以下内容：

path = /my/root/directory
for x in list_of_vars:
        if os.path.isdir(path + '/' + x):  # line A
            print(x + ' exists.')
        else:
            os.mkdir(path + '/' + x)       # line B
            print(x + ' created.')

For lines A and B as shown above, is there a better way to create a file path as this will become longer the deeper I delve into the directory tree?

对于如上所示的 A 行和 B 行，是否有更好的方法来创建文件路径，因为我越深入研究目录树，路径就会变得越长？

I envisage an existing built-in method to be used as follows:

我设想使用现有的内置方法如下：

create_path(path, 'in', 'here')

producing a path of the form /my/root/directory/in/here

生成表单的路径 /my/root/directory/in/here

If there is no built in function I will just write myself one.

如果没有内置函数，我就自己写一个。

Thank you for any input.

感谢您提供任何意见。

采纳答案by kennytm

Yes there is such a built-in function: os.path.join.

是的，有这样一个内置函数：os.path.join.

>>> import os.path
>>> os.path.join('/my/root/directory', 'in', 'here')
'/my/root/directory/in/here'

回答by nmichaels

You want the path.join() function from os.path.

您需要 os.path 中的 path.join() 函数。

>>> from os import path
>>> path.join('foo', 'bar')
'foo/bar'

This builds your path with os.sep (instead of the less portable '/') and does it more efficiently (in general) than using +.

这会使用 os.sep （而不是不太便携的'/'）构建您的路径，并且比使用.sep更有效（通常）+。

However, this won't actually create the path. For that, you have to do something like what you do in your question. You could write something like:

但是，这实际上不会创建路径。为此，您必须做一些类似于您在问题中所做的事情。你可以这样写：

start_path = '/my/root/directory'
final_path = os.join(start_path, *list_of_vars)
if not os.path.isdir(final_path):
    os.makedirs (final_path)

回答by AlexandreS

You can also use an object-oriented path with pathlib(available as a standard library as of Python 3.4):

您还可以使用面向对象的路径pathlib（作为 Python 3.4 的标准库提供）：

from pathlib import Path

start_path = Path('/my/root/directory')
final_path = start_path / 'in' / 'here'