受到andrei-deusteanu答案的启发，以下是我的版本。这允许您在site-packages目录中创建许多额外的路径。

import os

# Add paths here.  Then Run this block of code once and restart kernel. Paths should now be set.
paths_of_directories_to_add = [r'C:\GIT\project1', r'C:\GIT\project2', r'C:\GIT\project3']

# Find your site-packages directory
pathSitePckgs = os.path.join(os.path.dirname(os.__file__), 'site-packages')

# Write a .pth file in your site-packages directory
pthFile = os.path.join(pathSitePckgs,'current_machine_paths.pth')
with open(pthFile,'w') as pth_file:
    pth_file.write('\n'.join(paths_of_directories_to_add))

print(pthFile)

为了给出更多的解释，Python将使用site.py脚本(通常位于sys. py中)自动构造它的搜索路径(如上所述和这里)。Prefix + lib/python<version>/site-packages以及lib/site-python)。可以获取sys.prefix的值:

python -c 'import sys; print(sys.prefix)'

The site.py script then adds a number of directories, dependent upon the platform, such as /usr/{lib,share}/python<version>/dist-packages, /usr/local/lib/python<version>/dist-packages to the search path and also searches these paths for <package>.pth config files which contain specific additional search paths. For example easy-install maintains its collection of installed packages which are added to a system specific file e.g on Ubuntu it's /usr/local/lib/python2.7/dist-packages/easy-install.pth. On a typical system there are a bunch of these .pth files around which can explain some unexpected paths in sys.path:

python -c 'import sys; print(sys.path)'

因此，可以创建一个.pth文件，并将其放在这些目录中的任何一个目录中(包括上面提到的sitedir)。这似乎是大多数包被添加到系统的方式。而不是使用PYTHONPATH。

Note: On OSX there's a special additional search path added by site.py for 'framework builds' (but seems to work for normal command line use of python): /Library/Python/<version>/site-packages (e.g. for Python2.7: /Library/Python/2.7/site-packages/) which is where 3rd party packages are supposed to be installed (see the README in that dir). So one can add a path configuration file in there containing additional search paths e.g. create a file called /Library/Python/2.7/site-packages/pip-usr-local.pth which contains /usr/local/lib/python2.7/site-packages/ and then the system python will add that search path.

向PYTHONPATH添加新路径是手动执行的:

将路径添加到~/。Bashrc剖面，在终端由:

vim ~/.bashrc

将以下内容粘贴到您的配置文件中

export PYTHONPATH="${PYTHONPATH}:/User/johndoe/pythonModule"

然后，当你在终端中运行你的代码时，确保你的bashrc配置文件的来源:

source ~/.bashrc 

希望这能有所帮助。

下面的脚本可以在所有平台上运行，因为它是纯Python。它使用了pathlib路径(请参阅https://docs.python.org/3/library/pathlib.html)，使其能够跨平台工作。运行一次，重新启动内核，就完成了。灵感来自https://medium.com/@arnaud.bertrand/ modiing-python-s - sear-path-with-pth -files-2a41a4143574。为了运行它，它需要管理员权限，因为你修改了一些系统文件。

from pathlib import Path
to_add=Path(path_of_directory_to_add)
from sys import path

if str(to_add) not in path:
    minLen=999999
    for index,directory in enumerate(path):
        if 'site-packages' in directory and len(directory)<=minLen:
            minLen=len(directory)
            stpi=index
            
    pathSitePckgs=Path(path[stpi])
    with open(str(pathSitePckgs/'current_machine_paths.pth'),'w') as pth_file:
        pth_file.write(str(to_add))

如果您正在使用bash(在Mac或GNU/Linux发行版上)，请将此添加到~/.bashrc中

export PYTHONPATH="${PYTHONPATH}:/my/other/path"

您需要将新目录添加到环境变量PYTHONPATH中，以冒号与之前的内容分隔。在任何形式的Unix中，您都可以在适合于您使用的任何shell的启动脚本中完成(。配置文件或其他，取决于你最喜欢的shell)与一个命令，同样，取决于所讨论的shell;在Windows中，您可以通过系统GUI来实现此目的。

Superuser.com可能是一个更好的地方，可以进一步询问，例如，如果您需要详细说明如何在所选的平台和shell中丰富环境变量，可以询问更多细节，因为这本身并不是一个真正的编程问题。