Python package import from parent directory

Question

I've the following source code structure

/testapp/
/testapp/__init__.py
/testapp/testmsg.py
/testapp/sub/
/testapp/sub/__init__.py
/testapp/sub/testprinter.py

where testmsg defines the following constant:

MSG = "Test message"

and sub/testprinter.py:

import testmsg

print("The message is: {0}".format(testmsg.MSG))

But I'm getting ImportError: No module named testmsg

Shouldn't it be working since the package structure? I don't really want to extend sys.path in each submodule and I don't even want to use relative import.

What am I doing wrong here?

Answer 1

It all depends on which script you run. That script's path will be added to python's search path automatically.

Make it the following structure:

TestApp/
TestApp/README
TestApp/LICENSE
TestApp/setup.py
TestApp/run_test.py
TestApp/testapp/__init__.py
TestApp/testapp/testmsg.py
TestApp/testapp/sub/
TestApp/testapp/sub/__init__.py
TestApp/testapp/sub/testprinter.py

Then run TestApp/run_test.py first:

from testapp.sub.testprinter import functest ; functest()

Then TestApp/testapp/sub/testprinter.py could do:

from testapp.testmsg import MSG
print("The message is: {0}".format(testmsg.MSG))

More good hints here;