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.

Linux:导入的模块位于/usr/local/lib/python2.7/dist-packages中

如果你使用的是C语言编译的模块，不要忘记在sudo setup.py install后chmod .so文件。

sudo chmod 755 /usr/local/lib/python2.7/dist-packages/*.so

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.

你正在阅读这个答案说你的__init__.py是在正确的地方，你已经安装了所有的依赖项，你仍然得到ImportError。

我也遇到了类似的问题，除了我的程序在使用PyCharm运行时运行良好，但当我从终端运行时出现上述错误。在深入研究之后，我发现PYTHONPATH没有项目目录的条目。所以，我设置PYTHONPATH每个Import语句在PyCharm上工作，但不是从终端:

export PYTHONPATH=$PYTHONPATH:`pwd`  (OR your project root directory)

还有另一种方法可以使用sys。路径为:

import sys
sys.path.insert(0,'<project directory>') OR
sys.path.append('<project directory>')

您可以根据希望搜索项目的顺序使用插入/追加。

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

对我来说，这是件非常愚蠢的事。我使用pip3 install安装了这个库，但是我运行的程序是python program.py，而不是python3 program.py。