I have written a module (a file my_mod.py file residing in the folder my_module). Currently, I am working in the file cool_script.py that resides in the folder cur_proj. I have opened the folder in PyCharm using File -- open (and I assume, hence, it is a PyCharm project).

In ProjectView (CMD-7), I can see my project cur_proj (in red) and under "External Libraries" I do see my_module. In cool_script.py, I can write

from my_module import my_mod as mm

and PyCharm even makes suggestion for my_mod. So far so good.

However, when I try to run cool_script.py, PyCharm tells me "No module named my_module"

This seems strange to me, because

A) in the terminal (OS 10.10.2), in python, I can import the module no problem -- there is a corresponding entry in the PYTHONPATH in .bashrc

B) in PyCharm -- Settings -- Project cur_proj -- Project Interpreter -- CogWheel next to python interpreter -- more -- show paths for selected interpreter icon, the paths from PYTHONPATH do appear (as I think they should)

Hence, why do I get the error when I try to run cool_script.py? -- What am I missing?

Notes:

• I am not declaring a different / special python version at the top of cool_script.py
• I made sure that the path to my_module is correct
• I put __init__.py files (empty files) both in my_module and in cur_proj
• I am not using virtualenv

Addendum 2015-Feb-25

When I go in PyCharm to Run -- Edit Configurations, for my current project, there are two options that are selected with a check mark: "Add content roots to PYTHONPATH" and "Add source roots to PYTHONPATH". When I have both unchecked, I can load my module.

So it works now -- but why?

Further questions emerged:

• What are "content roots" and what are "source roots"? And why does adding something to the PYTHONPATH make it somehow break?
• should I uncheck both of those options all the time (so also in the defaults, not only the project specific configurations (left panel of the Run/Debug Configurations dialog)?

If your own module is in the same path, you need mark the path as Sources Root. In the project explorer, right-click on the directory that you want import. Then select Mark Directory As and select Sources Root.

So if you go to

-> Setting -> Project:My_project -> Project Structure,

Just the directory in which the source code is available and mark it as "Sources" (You can see it on the same window). The directory with source code should turn blue. Now u can import in modules residing in same directory.

PyCharm Community/Professional 2018.2.1

I was having this problem just now and I was able to solve it in sort of a similar way that @Beatriz Fonseca and @Julie pointed out.

If you go to File -> Settings -> Project: YourProjectName -> Project Structure, you'll have a directory layout of the project you're currently working in. You'll have to go through your directories and label them as being either the Source directory for all your Source files, or as a Resource folder for files that are strictly for importing.

You'll also want to make sure that you place __init__.py files within your resource directories, or really anywhere that you want to import from, and it'll work perfectly fine.

What I tried is to source the location where my files are.

e.g. E:\git_projects\My_project\__init__.py is my location.

I went to File -> Setting -> Project:My_project -> Project Structure and added the content root to about mention place E:\git_projects\My_project

it worked for me.

I was getting the error with "Add source roots to PYTHONPATH" as well. My problem was that I had two folders with the same name, like project/subproject1/thing/src and project/subproject2/thing/src and I had both of them marked as source root. When I renamed one of the "thing" folders to "thing1" (any unique name), it worked.

Maybe if PyCharm automatically adds selected source roots, it doesn't use the full path and hence mixes up folders with the same name.