从另一个目录运行Python脚本

Question

First, imagine the following file structure:

project-dir
|_ 
   package1
   |_ 
      __init__.py
      module1.py
      module2.py

And the following script contents:

module2.py:

def func_module2():
    print('func_module2 run')

module1.py:

from package1 import module2

module2.func_module2()

The following command creates an error when executed from the project-dir:

python package1/module1.py

Error:

Traceback (most recent call last):
  File "./package1/module1.py", line 1, in <module>
    from package1 import module2
ImportError: No module named 'package1'

Why is this happening and how is it possible to run a Python script from another directory?

Python 3.5.2

Answer 1

Your problem seem to be that module1.py and module2.py both lives in the same package. From module1.py you won't find module2.py in another package. Instead try:

import module2

module2.func_module()

Trying that I get:

> python package1/module1.py
func_module2 run

However if you want it to work as a package too (or using newer versions of python), you must istead use

from . import module2

module2.func_module()

but that will make python package1/module1.py not work since it will not be run as part of a package. Instead you can use

> python -m package1.module1
func_module2 run

Answer 2

module2 and module1 are under the same namespace. So it MUST be:

# module1.py
import module2

module2.func_module2()

from package1 import module2 is valid only in the following context/namespace:

Exemple:

# test.py
from package1 import module2

module2.func_module2()