TL;DR
Here's an example repository that is set up as described in the first diagram (below): https://github.com/Poddster/package_problems
If you could please make it look like the second diagram in terms of project organisation and can still run the following commands, then you've answered the question:
$ git clone https://github.com/Poddster/package_problems.git $ cd package_problems <do your magic here> $ nosetests $ ./my_tool/my_tool.py $ ./my_tool/t.py $ ./my_tool/d.py (or for the above commands, $ cd ./my_tool/ && ./my_tool.py is also acceptable)
Alternatively: Give me a different project structure that allows me to group together related files ('package'), run all of the files individually, import the files into other files in the same package, and import the packages/files into other package's files.
I have a bunch of python files. Most of them are useful when callable from the command line i.e. they all use argparse and if __name__ == "__main__"
to do useful things.
Currently I have this directory structure, and everything is working fine:
. ├── config.txt ├── docs/ │ ├── ... ├── my_tool.py ├── a.py ├── b.py ├── c.py ├── d.py ├── e.py ├── README.md ├── tests │ ├── __init__.py │ ├── a.py │ ├── b.py │ ├── c.py │ ├── d.py │ └── e.py └── resources ├── ...
Some of the scripts import
things from other scripts to do their work. But no script is merely a library, they are all invokable. e.g. I could invoke ./my_tool.py
, ./a.by
, ./b.py
, ./c.py
etc and they would do useful things for the user.
"my_tool.py" is the main script that leverages all of the other scripts.
However I want to change the way the project is organised. The project itself represents an entire program useable by the user, and will be distributed as such, but I know that parts of it will be useful in different projects later so I want to try and encapsulate the current files into a package. In the immediate future I will also add other packages to this same project.
To facilitate this I've decided to re-organise the project to something like the following:
. ├── config.txt ├── docs/ │ ├── ... ├── my_tool │ ├── __init__.py │ ├── my_tool.py │ ├── a.py │ ├── b.py │ ├── c.py │ ├── d.py │ ├── e.py │ └── tests │ ├── __init__.py │ ├── a.py │ ├── b.py │ ├── c.py │ ├── d.py │ └── e.py ├── package2 │ ├── __init__.py │ ├── my_second_package.py | ├── ... ├── README.md └── resources ├── ...
However, I can't figure out an project organisation that satisfies the following criteria:
my_tool\a.py
or cd my_tool && a.py
)import my_tool
The main problem is with the import statements used by the packages and the tests.
Currently, all of the packages, including the tests, simply do import <module>
and it's resolved correctly. But when jiggering things around it doesn't work.
Note that supporting py2.7 is a requirement so all of the files have from __future__ import absolute_import, ...
at the top.
If I move the files around as shown above, but leave all of the import statements as they currently are:
$ ./my_tool/*.py
works and they all run properly$ nosetests
run from the top directory doesn't work. The tests fail to import the packages scripts.If I then change the test scripts to do:
from my_tool import x
$ ./my_tool/*.py
still works and they all run properly$ nosetests
run from the top directory doesn't work. Then tests can import the correct scripts, but the imports in the scripts themselves fail when the test scripts import them. If I keep the same structure and change everything to be from my_tool import
then:
$ ./my_tool/*.py
results in ImportError
s $ nosetests
runs everything ok. e.g. of 1.:
Traceback (most recent call last): File "./my_tool/a.py", line 34, in <module> from my_tool import b ImportError: cannot import name b
I also tried from . import x
but that just ends up with ValueError: Attempted relative import in non-package
for the direct running of scripts.
I can't just use python -m pkg.tests.core_test
as
a) I don't have main.py. I guess I could have one?
b) I want to be able to run all of the scripts, not just main?
I've tried:
if __name__ == '__main__' and __package__ is None: from os import sys, path sys.path.append(path.dirname(path.dirname(path.abspath(__file__))))
but it didn't help.
I also tried:
__package__ = "my_tool" from . import b
But received:
SystemError: Parent module 'loading_tool' not loaded, cannot perform relative import
adding import my_tool
before from . import b
just ends up back with ImportError: cannot import name b
What's the correct set of magical incantations and directory layout to make all of this work?
Organize your modules into packages. Each package must contain a special __init__.py file. Your project should generally consist of one top-level package, usually containing sub-packages. That top-level package usually shares the name of your project, and exists as a directory in the root of your project's repository.
A Python package is nothing but a collection of modules along with a __init__.py file. The modules can also be arranged in hierarchy of folders inside a package. Just by adding an empty __init__.py file to the in the folder, Python knows it is a Package.
Once you move to your desired configuration, the absolute imports you are using to load the modules that are specific to my_tool
no longer work.
You need three modifications after you create the my_tool
subdirectory and move the files into it:
Create my_tool/__init__.py
. (You seem to already do this but I wanted to mention it for completeness.)
In the files directly under in my_tool
: change the import
statements to load the modules from the current package. So in my_tool.py
change:
import c import d import k import s
to:
from . import c from . import d from . import k from . import s
You need to make a similar change to all your other files. (You mention having tried setting __package__
and then doing a relative import but setting __package__
is not needed.)
In the files located in my_tool/tests
: change the import
statements that import the code you want to test to relative imports that load from one package up in the hierarchy. So in test_my_tool.py
change:
import my_tool
to:
from .. import my_tool
Similarly for all the other test files.
With the modifications above, I can run modules directly:
$ python -m my_tool.my_tool C! D! F! V! K! T! S! my_tool! my_tool main! |main tool!||detected||tar edit!||installed||keys||LOL||ssl connect||parse ASN.1||config| $ python -m my_tool.k F! V! K! K main! |keys||LOL||ssl connect||parse ASN.1|
and I can run tests:
$ nosetests ........ ---------------------------------------------------------------------- Ran 8 tests in 0.006s OK
Note that I can run the above both with Python 2.7 and Python 3.
Rather than make the various modules under my_tool
be directly executable, I suggest using a proper setup.py
file to declare entry points and let setup.py
create these entry points when the package is installed. Since you intend to distribute this code, you should use a setup.py
to formally package it anyway.
Modify the modules that can be invoked from the command line so that, taking my_tool/my_tool.py
as example, instead of this:
if __name__ == "__main__": print("my_tool main!") print(do_something())
You have:
def main(): print("my_tool main!") print(do_something()) if __name__ == "__main__": main()
Create a setup.py
file that contains the proper entry_points
. For instance:
from setuptools import setup, find_packages setup( name="my_tool", version="0.1.0", packages=find_packages(), entry_points={ 'console_scripts': [ 'my_tool = my_tool.my_tool:main' ], }, author="", author_email="", description="Does stuff.", license="MIT", keywords=[], url="", classifiers=[ ], )
The file above instructs setup.py
to create a script named my_tool
that will invoke the main
method in the module my_tool.my_tool
. On my system, once the package is installed, there is a script located at /usr/local/bin/my_tool
that invokes the main
method in my_tool.my_tool
. It produces the same output as running python -m my_tool.my_tool
, which I've shown above.
I believe it's working, so I don't comment on it.
I always used tests at the same level as my_tool, not below it, but they should work if you do this at the top of each tests files (before importing my_tool or any other py file in the same directory)
import os import sys sys.path.insert(0, os.path.abspath(__file__).rsplit(os.sep, 2)[0])
In my_second_package.py do this at the top (before importing my_tool)
import os import sys sys.path.insert(0, os.path.abspath(__file__).rsplit(os.sep, 2)[0] + os.sep + 'my_tool')
Best regards,
JM
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