在我的例子中，我使用sys.path.insert()导入一个本地模块，并从其他库中找不到模块。我不得不把sys.path.insert()放在报告模块未找到的导入下面。我认为最好的做法是将sys.path.insert()放在导入的底部。

在*nix上，还要确保PYTHONPATH配置正确，特别是它具有以下格式:

 .:/usr/local/lib/python

(注意开头的.:，这样它也可以在当前目录上搜索。)

它也可能在其他位置，取决于版本:

 .:/usr/lib/python
 .:/usr/lib/python2.6
 .:/usr/lib/python2.7 and etc.

在ubuntu apt-get安装程序中，python3版本的包通常被命名

python3-XYZ

以及python2版本

python-XYZ

根据经验，请尝试错误消息中提到的包的python3-XYZ或python-XYZ。 不需要猜测，使用RegEx搜索apt缓存。然后:

$ apt-cache search "python.*toolkit.*interface"
python3-cli-helpers - easy command-line apps with Python
python3-exam - Python module to help write better tests
python3-fltk - Python wrapper for the Fast Light Toolkit
python3-mpltoolkits.basemap - matplotlib toolkit to plot on map projections (Python 3)
python3-nltk - Python3 libraries for natural language processing
python3-onnx - Open Neural Network Exchange (ONNX) (Python)
python3-paraview - Parallel Visualization Application. python-support
python3-pyswarms - research toolkit for particle swarm optimization in Python
python3-wxgtk-media4.0 - Python 3 interface to the wxWidgets Cross-platform C++ GUI toolkit (wx.media)
python3-wxgtk-webview4.0 - Python 3 interface to the wxWidgets Cross-platform C++ GUI toolkit (wx.html2)
python3-wxgtk4.0 - Python 3 interface to the wxWidgets Cross-platform C++ GUI toolkit
python3-xapian - Xapian search engine interface for Python3
wxglade - GUI designer written in Python with wxPython

它没有找到它。

请注意，这种apt-get技巧有时也需要用于依赖的包。

我对python2.7的flask包有相同的错误消息，当我尝试时它消失了:

sudo apt-get install python-flask

因此,试一试:

sudo apt-get install python-[YOURPYTHONVERION]-[YOURERRORPACKAGE]

或者检查上面提到的依赖关系。

当我在LPTHW中做这个练习时，我遇到了非常相似的情况;我永远无法让Python识别我调用的目录中有文件。但最后我还是让它工作了。我所做的，以及我所推荐的，是这样做的:

(注意:从你最初的文章中，我假设你使用的是基于* nix的机器，并从命令行运行，所以这个建议是为你量身定做的。因为我运行Ubuntu，这是我所做的)

Change directory (cd) to the directory above the directory where your files are. In this case, you're trying to run the mountain.py file, and trying to call the toolkit.interface.py module, which are in separate directories. In this case, you would go to the directory that contains paths to both those files (or in other words, the closest directory that the paths of both those files share). Which in this case is the toolkit directory. When you are in the toolkit directory, enter this line of code on your command line: export PYTHONPATH=. This sets your PYTHONPATH to ".", which basically means that your PYTHONPATH will now look for any called files within the directory you are currently in, (and more to the point, in the sub-directory branches of the directory you are in. So it doesn't just look in your current directory, but in all the directories that are in your current directory). After you've set your PYTHONPATH in the step above, run your module from your current directory (the toolkit directory). Python should now find and load the modules you specified.

我的问题是，我将带有__init__.py文件的目录添加到PYTHONPATH，而实际上我需要添加它的父目录。

另一个原因导致了这个问题

file.py

#!/bin/python
from bs4 import BeautifulSoup

如果你的默认python是pyyhon2

$ file $(which python)
/sbin/python: symbolic link to python2

File.py在这种情况下需要python3 (bs4) 你不能像这样用python2执行这个模块:

$ python file.py
# or
$ file.py
# or
$ file.py # if locate in $PATH

两种方法来修复这个错误，

# should be to make python3 as default by symlink
$ rm $(which python) && ln -s $(which python3) /usr/bin/python
# or use alias
alias python='/usr/bin.../python3'

或者将file.py中的shebang修改为

#!/usr/bin/...python3