Let's say Tight Ars & Co. is a company with incredibly tight security policies, and lets assume I work for this company.  Assume they've one task that requires a python script to write to excel files, and I find this incredibly wonderful library called xlwt. Now my script is able to write to excel files, everything is wonderful and the sun is shining, I release the code, and suddenly I'm asked what is this thingamajig setup.py, why should we run it? wait, we'll not even run it, we want the environment to be clean from third party code etc etc, since I'm unaware of any wizardry or voo doo is there any way I can package the dependent libraries and import them in my script?
All setup.py typically does with any pure-Python package is copy files into a standard place and compile the .py files to .pyc. I can't imagine why your employer would regard that as (nasty) third-party software, but the source of the package is OK, your IDE is OK, Python itself is OK, etc ...
Options:
(1) Copy the xlwt directory from a source distribution to somewhere that's listed in sys.path
(2) Make a ZIP file xlwt.zip containing the contents of the xlwt directory and copy it to ditto.
(3) As (2) but compile the .py files to .pyc first.
If somebody points out that the above involves error-prone manual steps, you can:
(a) write a script to do that
or
(b) copy setup.py, change its name, pretend that you wrote it yourself, use it, ...
Python import module (xlwt) from archive