Python unable to import custom module despite having init.py

Question

I have a folder with a __init__.py

File __init__.py:

#!/usr/bin/python2
flags="test"

File main.py:

#!/usr/bin/python2
import foldername

def main():
    print foldername.flags

if __name__ == '__main__':
main()

Now, when I run ./main.py (from inside the folder), I get the error

ImportError: No module named foldername

Make sure, that the parent directory of `foldername` is in your python path (environment variable `PYTHONPATH`). — Dirk, Feb 01 '12 at 19:15
Make sure your foldername is *not* also `main`. And `main.py` should *not* be inside the same folder. — Has QUIT--Anony-Mousse, Feb 01 '12 at 19:30
@Anony-Mousse: `main.py` may be inside the same folder. Python 2.7 even supports it explicitly with `__main__.py` name. — jfs, Feb 01 '12 at 19:38

score 7 · Accepted Answer · edited Jun 04 '20 at 21:25

7

Run from the parent folder for foldername:

    $ python -m foldername.main

If you rename main.py to __main__.py then you could run it as (since Python 2.7):

    $ python -m foldername

python -m adds implicitly current directory to your python path (sys.path).

Parent Folder/
└── foldername
    ├── __init__.py
    │   #    flags="test"
    └── __main__.py
        #    import foldername
        #   
        #    def main():
        #        print foldername.flags
        #   
        #    if __name__=="__main__":
        #        main()

If the parent directory for foldername is in your python path then you could run the above commands from any directory.

edited Jun 04 '20 at 21:25

Mehant Kammakomati

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answered Feb 01 '12 at 19:14

jfs

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Running from the parent folder of main gives: /usr/bin/python2: No module named foldername – jck Feb 01 '12 at 19:23
@jck: move one directory up i.e., use the parent folder of *folder* "foldername". – jfs Feb 01 '12 at 19:25
Sorry. running from the home directory(Parent folder of foldername) also gives the same error. – jck Feb 01 '12 at 19:27
@jck: I've added the directory layout. It should be clear what the "Parent Folder" is. – jfs Feb 01 '12 at 19:53

score 5 · Answer 2 · edited May 23 '17 at 11:46

5

PYTHONPATH issue. Make sure that "foldername" is available in your path. If you are running it from inside "foldername" it might not be available. Try running from the parent of "foldername".

Here is a question about finding your PYTHONPATH.

edited May 23 '17 at 11:46

Community

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answered Feb 01 '12 at 19:19

istruble

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It is not `PYTHONPATH` issue. It is python path issue (`sys.path`). My `PYTHONPATH` environment variable is always empty. `python` implicitly adds script's directory to `sys.path`. Sometimes It is called `sys.path[0]` initialization for scripts. – jfs Feb 01 '12 at 20:01
1

Wow, this solved my mystery problem! I did not realize the parent path must also be in the PYTHONPATH! So the same script sitting a level above what I want to import runs fine. But once I move it into some sub-directory, it won't import even with the right sys.path - until I add the parent dir to sys.path that is. Thanks! – Evgen May 21 '16 at 00:28

score 3 · Answer 3 · answered Feb 01 '12 at 19:33

3

Make sure your layout is like this:

./folder/__init__.py
./main.py

and there is not file named folder.py!

Change to the parent folder, so that ls folder/__init__.py works.

Next try running python -c "import folder".

answered Feb 01 '12 at 19:33

Has QUIT--Anony-Mousse

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score 0 · Answer 4 · answered Apr 22 '19 at 12:20

0

If you want to import the a module in python3 simply go to the root folder

python3 -mModuleName

Make sure you do not remove the -m before the module name and then this you can import this module anywhere inside the project directory.

answered Apr 22 '19 at 12:20

Sundeep Pidugu

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Python unable to import custom module despite having __init__.py

4 Answers4

Python unable to import custom module despite having init.py