Import paths - the right way?

I know there are A LOT of similar or the same questions, but i still cannot understand / find the right way for me to work with modules. Python is my favorite language, and i like everything in it except working with imports: recursive imports (when you try to reference a name that is not yet there), import paths, etc.

So, I have this kind of a project structure:

my_project/
    package1/
        __init__.py
        module1
        module2
    package2/
        __init__.py
        module1
        module2

Package1 may be used a standalone unit, but is also expected to be imported by package2. What am i doing now, is that, for example, in package1.module1 i write from package1 import module2, i.e. using full path to imported module. I do this because if i use import module2 -- this will not work when the module will be imported from another package (package2). I also cannot use from . import module2 -- this will not work when running module1 directly.

OK, so for from package1 import module2 in package1.module1 to work in both cases (when running directly package1.module1 and when importing it from package2) i add these lines at the beginning of package1.module1:

import os, sys
currDir = os.path.dirname(os.path.realpath(__file__))
rootDir = os.path.abspath(os.path.join(currDir, '..'))
if rootDir not in sys.path: # add parent dir to paths
    sys.path.append(rootDir)

For me this works, but i feel this is not pythonic. Am i doing something wrong?

Should i, instead, always run package1.module1 from project root? If so, this makes inconvenient to run it from an IDE -- i need somehow to set paths in it.

UPDATE: I tried to add a file root.pth to package1 dir with conten