Python - what is the libs subfolder for?

Question

For me, it's located at C:\Python33\libs.

For reference - this is not the same folder as C:\Python33\Lib - note the capitalization and lack of an 's'.

On one computer I was working on, I simply dropped a .py file into the libs folder and could import and use it like a library / module (sorry, I don't really know terminology very well), regardless of where the project I was working on is.

However, in trying to duplicate this on another machine, this doesn't work. Attempting to import simply gives a "no module named X" error.

So, clearly I'm misunderstanding the purpose of the libs folder, and how it differs from the Lib folder.

So, what exactly is the difference?

Answer 1

If you compare libs/ vs. Lib/ you'll notice that the latter is full of *.py files and the former has *.lib files. Further investigation with a text editor will show that *.py files are human-readable (I hope) and the *.lib files are not.

And that's really the difference. If you want to know more, the .lib files are static-link libraries, used for building .dlls, C extensions, and all that good stuff. Head on down the rabbit hole if that interests you.

On to the meat of your question: are you supposed to be able to drop modules in there and be able to import them? Not really. That is a side effect of that folder being included in your path. From the Modules docs:

When a module named spam is imported, the interpreter first searches for a built-in module with that name. If not found, it then searches for a file named spam.py in a list of directories given by the variable sys.path. sys.path is initialized from these locations:

• the directory containing the input script (or the current directory).
• PYTHONPATH (a list of directory names, with the same syntax as the shell variable PATH).
• the installation-dependent default.

Various installation methods will modify %PATH% or %PYTHONPATH% so I can't tell you exactly where to look; on my windows box, the python installer modified %PATH% for me, so you should probably look there first. Notably, my path does not include Python33/libs/ so I would not expect it to be there by default.

Answer 2

Just looking on mine (Windows 7) /libs appears to be the native code libraries (*.lib) vs the straight python libraries in /Lib. The readme also mentions a configuration flag:

--with-libs='libs': Add 'libs' to the LIBS that the python interpreter is linked against.

Which may or may not be set on different installs/platforms.

This isn't really a answer; hopefully someone with a firmer knowledge of it will explain further - was just a bit too much info to squeeze into a comment.