在另一个文件夹中导入python3

Question

When I run launch.py it fails and when I run main.py directly it works. launch.py just imports and runs main.py. Why?

├── dir
│   ├── bla.py
│   ├── __init__.py
│   └── main.py
├── __init__.py
└── launch.py

launch.py
---------
    #!/usr/bin/env python
    # -*- coding: utf-8 -*-

    from dir import main
    main.main()

main.py
-------

    #!/usr/bin/env python
    # -*- coding: utf-8 -*-
    import bla
    bla.pront()


bla.py
------

def pront():
    print('pront')

EDITED:

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Answer 1

Using your layout and with the following files, we don't have problems.

launch.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from dir import main

if __name__ == "__main__":
   main. main()

main.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
try:
    from . import bla
except:
    import bla

def main():
    bla.pront()

if __name__ == "__main__":
    main()

The try ... except structure is used in case the main.py was used inside or outside the package.

Of course, there is a lot of info about it. You can start with this .

Answer 2

I believe I see the answer...
You have not defined main, perhaps try that. The reason why it works when called directly is because Python scripts are run in the order in which functions appear unless a specific function is called.

Try changing main.py to

import bla
def mainfunction():
    bla.pront()

Then change launch.py to

import main
main.mainfunction()

I hope this helps! :)