Python: No module named contextlib?

It has been part of the standard library since 2.5 according to the docs. It seems a bit weird that you don't have it, it works with 2.6.6 for me (Ubuntu 10.10):

blair@blair-eeepc:~$ python
Python 2.6.6 (r266:84292, Sep 15 2010, 15:52:39) 
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import contextlib
>>> contextlib.__file__
'/usr/lib/python2.6/contextlib.pyc'

Somebody may have a better suggestion, but if it comes to it there is a link at the top of the documentation to the source code (which is Python, so you should be able to use it directly without any compilation or anything).

Edit: Unless, as Santiago Lezica suggested, you compiled your copy of Python manually, in which case it should be a simple matter of copying the module into the correct library path.

Edit for updated question: To the best of my knowledge, just dropping the source into a directory on the Python path should work. You could do this in the system library, but, to avoid it being deleted/replaced/otherwise borked in future updates, I'd recommend putting it in a separate directory and adding that directory to the Python path. You could put it under /usr/local, or somewhere in your home directory.

As others have noted, that module should be in the standard library, but if it's an embedded device, it may have been dropped to save space (if true, a foolish choice IMO, since leaving out contextlib.contextmanager robs the with statement of much of its power and convenience)

If you can name the specific device or manufacturer (or ask the vendor directly), you may be able to get a better answer.

As far as fixing it goes, grabbing http://hg.python.org/cpython/file/2.6/Lib/contextlib.py and dropping it in sys.path somewhere should do the trick (running python -m site will dump the list of directories that you can use)

I got this error in a different way.

I created a pipenv virtual environment using the 32bit version of Python 3.6.5 on Windows 10. I then realized I needed the 64bit version. Uninstalled the 32bit, installed the 64bit, and then tried to go back to my existing virtual env. The previously created env was now broken in odd ways and gave me this error.

I solved this by removing the old pipenv pipenv --rm and creating a new one with the newly installed version of python.