Trimming Python Runtime

Question

We've got a (Windows) application, with which we distribute an entire Python installation (including several 3rd-party modules that we use), so we have consistency and so we don't need to install everything separately. This works pretty well, but the application is pretty huge.

Obviously, we don't use everything available in the runtime. I'd like to trim down the runtime to only include what we really need.

I plan on trying out py2exe, but I'd like to try and find another solution that will just help me remove the unneeded parts of the Python runtime.

Answer 1

One trick I've learned while trimming down .py files to ship: Delete all the .pyc files in the standard library, then run your application throughly (that is, enough to be sure all the Python modules it needs will be loaded). If you examine the standard library directories, there will be .pyc files for all the modules that were actually used. .py files without .pyc are ones that you don't need.

Answer 2

Both py2exe and pyinstaller (NOTE: for the latter use the SVN version, the released one is VERY long in the tooth;-) do their "trimming" via modulefinder, the standard library module for finding all modules used by a given Python script; you can of course use the latter yourself to identify all needed modules, if you don't trust pyinstaller or py2exe to do it properly and automatically on your behalf.

Answer 3

This py2exe page on compression suggests using UPX to compress any DLLs or .pyd files (which are actually just DLLs, still). Obviously this doesn't help in trimming out unneeded modules, but it can/will trim down the size of your distribution, if that's a large concern.