python3中正确的文件夹结构

Question

Python 3.7.4 (homebrew)

I am trying to run script.py. It works fine in PyCharm when I run it, but when I try to run it from the command line I get an error.

Project structure:

project
  /folder
    /subfolder1
      /subfolder2
        /script.py
  /tools
    /subfolder
      /tool.py

I get this error when I try to run it from command line

from tools.subfolder.tool import *
ModuleNotFoundError: No module named 'tools'

Answer 1

Using an editor like PyCharm will temporarily add the project root directory (in your case, directory project/ ) to the PYTHONPATH. This means that you have the possibility of importing modules by using a path relative to the project root. That's why from tools.subfolder.tool import * works in PyCharm. If you wanted to run it from the command line, you could add your root directory to PYTHONPATH. For example, if you're using bash or zsh , you can append your project root to PYTHONPATH by running export PYTHONPATH="$PYTHONPATH:/path/to/project/root/" . You can also do that for just the current script by running:

import sys
sys.path.append('/path/to/project/root/')

You could also relatively specify the path to the project root. Say, your project root is in the directory holding the directory where your python script is located, you could do something like sys.path.append('..') instead.

Cheers.

Answer 2

A similar question has been asked here: https://stackoverflow.com/questions/24622041/python-importing-a-module-from-a-parallel-directory . Running a python script like yours from the terminal is a little bit different than just doing it normally, python subfolder1/subfolder2/script.py , because you have imports from outside the python script directory.

To do this you need to navigate into the root directory of your project with the cd command. In your case the folder called "Project" seems to be your project directory here. Secondly when you run the python script you should use python -m <python file directory> . For your project structure the command would be python -m folder.subfolder1.subfolder2.script

More information on this is in the link provided earlier. When you run a python script, for example, python subfolder1/subfolder2/script.py , it only adds subfolder2 to the PYTHONPATH so you can access files in the same directory, below it, but not above. Running it this way, python -m folder.subfolder1.subfolder2.script , will add the project directory to the path making everything in it accessible.

I hope this helps with answering your question.