This is a placeholder for general improvements to Python packaging infrastructure in Nixpkgs.

Documentation

• why do we use propagatedBuildInputs?
• how to generate PYTHONPATH out of packages? (makePythonPath in nix, and toPythonPath in bash)
• explain a bit in more detail how python setup hook works and that packages not using buildPythonPackage need to add python to propagatedBuildInputs (Python: some packages don't propagate python causing "nix-shell -p" to fail #17679, Python: split buildPythonPackage into two functions #18143)
• wrapPython
• how to use virtualenv with Nix? (Better documentation for python.buildEnv / virtualenv #5623, Document how to customize modules available to virtualenv #66)

Python modules

• add support for modules to all python interpreters (Python 3 dependency bloat #12333, Python: use separate output for tkinter #19309)
• enable readline by default (adds 16M to the closure (nixpkgs python repl isn't very terminal-friendly #17607, Python: use separate output for tkinter #19309)
• enable ncurses by default (Python 2.7 Full: sqlite3 module doesn't work in virtualenv #492 (comment), Python: use separate output for tkinter #19309)
• enable sqlite by default (Python 2.7 Full: sqlite3 module doesn't work in virtualenv #492 (comment), Python: use separate output for tkinter #19309)
• tkinter.tix doesn't yet function with $ nix-shell -p 'python.withPackages(ps: [ps.tkinter])' --run "python -c 'import Tix; Tix.Tk()'". Python tix module #21643 (review)

Build functions

• join python and buildPythonPackage setup-hooks
• namePrefix should be default empty and prefixed with pythonX.X- only inside python-packages.nix (buildPythonApplication: use new function for Python applications #13124)
• refactor buildPythonPackage into python.mkDerivation (similar to cabal.mkDerivation)
• helpers for python software that doesn't use distutils/setuptools (Python: split buildPythonPackage into two functions #18143)
• convert all mkDerivation using distutils to buildPythonPackage
• convert all buildPythonPackage not using distutils to mkDerivation Typically buildPythonPackage or buildPythonApplication with format = "other"; should be used. See the docs.
• replace magicalSedExpression (Replace magic sed for Python argv[0] with a python wrapper. #11168)
• buildPythonPackage shouldn't use postFixup (buildPythonPackage uses postFixup for itself #9204, 85a87f5)

Packages

• modernize packages in python-modules folder to be either a module or an application (versioned pythonX.Y- prefix #1468)
• pypi2nix: a tool to generate Nix expressions for Python packages.
• fixed-point combinator for python-packages.nix (Python: Fixed-point combinator #17428)
• autogenerated data with urls to and hashes for all PyPI packages (Python: buildPyPIPackage and generated data #16005, Autogenerated data in Nixpkgs #15480).

Tests

• it should be easier to run different test runners (setup.py / nosetests / py.test) (python buildPythonPackage: check and run correct test command #11715)
• hook for testing importing modules (f7e28bf)
• import all modules after building (python improvement: import all modules after the build is finished #3821, Python: default test runner fails often because it imports all modules #14849)
• reduce closure sizes by not installing tests (Python: reduce closure sizes by not installing tests #12379)

Issues to resolve

• Depend on a Python application without adding the libraries to PYTHONPATH (Depending on a python package without adding it to PYTHONPATH #11423)
• Tox (tox package broken #15224)
• virtualenv should use pythonFull (Make virtualenv use pythonFull, not python #7134, Python: use separate output for tkinter #19309)
• unify Python interpreters (together with pypy) (Python: move interpreters #17339)
• Nix replacement for ctypes.util.find_library ([python] ctypes.util.find_library should return full path to the library #7307)
• setuptools namespaces are broken (give collisions) (python: setuptools namespaces are broken (give collisions) #2412, python-wrapper broken by recent re-factoring #1826)
• data_files upstream issue (Patch upstream to correctly handle install_data/data_files in Python #4968)
• zc.recipe.egg is broken
• Circular dependencies
• pypy PYTHONPATH is incomplete (pypyPackages: wrapped scripts are missing paths from PYTHONPATH #12948)
• Python on Nix is not compatible with manylinux1 (Python on Nix claims to be manylinux compatible #18484, Add support for PEP 513 "manylinux1" wheels #71935)