ModuleNotFoundError: No module named 'pysteps.motion._vet'

[pysteps]

ModuleNotFoundError: No module named 'pysteps.motion._vet'

[aperezhortal]

Hi @wcwoo, this error is caused by the root pysteps repository folder being recognized as the pysteps package. Any directory on sys.path with a name that matches the package name (pysteps in this case) that is being looked for, will be recognized as contributing modules and sub-packages to that package. The error is happening because the the first directory in sys.path is the current working directory.

More information about this here.

[dnerini]

Hi @wcwoo!
What is your working directory?
I was able to reproduce your error when launching python from within the pysteps folder with the source code:

(pysteps) -bash-4.2$ pwd
/home/ned/pysteps
(pysteps) -bash-4.2$ python
Python 3.6.6 |Anaconda, Inc.| (default, Oct  9 2018, 12:34:16)
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import pysteps
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/ned/pysteps/pysteps/__init__.py", line 15, in <module>
    from . import motion
  File "/home/ned/pysteps/pysteps/motion/__init__.py", line 3, in <module>
    from .interface import get_method
  File "/home/ned/pysteps/pysteps/motion/interface.py", line 5, in <module>
    from pysteps.motion.vet import vet
  File "/home/ned/pysteps/pysteps/motion/vet.py", line 30, in <module>
    from pysteps.motion._vet import _warp, _cost_function
ModuleNotFoundError: No module named 'pysteps.motion._vet'
>>>

Moving to any other folder avoids the error:

(pysteps) -bash-4.2$ cd examples/
(pysteps) -bash-4.2$ pwd
/home/ned/pysteps/examples
(pysteps) -bash-4.2$ python
Python 3.6.6 |Anaconda, Inc.| (default, Oct  9 2018, 12:34:16)
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import pysteps
Pysteps configuration file found at: /home/ned/.pysteps/pystepsrc
>>>

I'm not sure what it's causing the problem, my guess is that there is some sort of path conflict when pysteps is imported from within its main directory. Do you have a better idea @aperezhortal? Is there an easy fix we can implement?

[wcwoo]

My working directory was just /home/wcwoo/pysteps. I confirm that invoking python from another directory avoids the problem. Thanks!

(pysteps) wcwoo@wcwoo-VirtualBox:~/pysteps$ cd examples
(pysteps) wcwoo@wcwoo-VirtualBox:~/pysteps/examples$ python
Python 3.6.7 | packaged by conda-forge | (default, Nov 21 2018, 03:09:43) 
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import pysteps
Pysteps configuration file found at: /home/wcwoo/.local/lib/python3.6/site-packages/pysteps-0.2-py3.6-linux-x86_64.egg/pysteps/pystepsrc

[dnerini]

OK, so this is actually normal behavior rather than a bug. Thanks @aperezhortal for the explanation!

[wcwoo]

I see. Thanks for your explanations.