Develop Reference

Pip skips a file from installation

I'm trying to deploy a new version of a project I've been working on. I zip the package into a .tar.gz file using the standard python setup.py sdist command, and then install the package using python -m pip install x.tar.gz.
All the files which are required are present in the archive itself (the .tar.gz file) but for some reason pip skips installing one of these, a binary file containing some lookup tables. Moreover, I think this happens only on linux (I make the package itself using Windows, and here everything works fine). I would think that this might have something to do with using sdist instead of bdist, but with previous versions I've had no issues of this kind, despite using the same method. I'm not sure if there is any architecture dependency at play here. Are all binary files architecture dependent?
Any ideas regarding what might be the cause of this?

Install python package into directory relative to site-packages

I have a Python package that is one of a collection of company Python packages. When I run
python setup.py install
I want the package to be installed to a common company directory, along with other company packages. I want this directory to be relative to the default Python install directory, e.g.,
/usr/lib/python2.7/site-packages/<company_name>/<python_package_name>
That is, I want to insert <company_name> into the installation path at install time.
I've seen ways to prefix this path, but can't seem to work out how to do what I've described.

Unfortunately Python packaging doesn't work like that. You could probably bend it to work like that but that would be quite an effort for a person without experience in Python packaging and even for experienced persons the amount/output tradeoff would not make sense. You do not mention any motive to do this besides your personal preference.
Instead, to have well-managed and human-navigable package installation folder, I recommend you to study the following resources
PEP 0382 - Namespace Packages: How to create packages like companyname.foobar, companyname.moomoo
Installing packages into a virtualenv - Python packaging installation guide (official)
Scrambler: Symlink namespaced Python packages to a single folder

Windows installer for Python module which includes dependencies

I have a python module with an entry point in its setup.py which points to __ main__.py. I want to be able to distribute this module to my coworkers in such a way that they can install it using a windows installer, and execute the entry point from the command line. They already have Python installed on their computer.
The built-in python setup.py bdist_wininst functionality looked perfect, except that my module has a third party module dependency, and for some reason, bdist_wininst does not install dependencies even if they are specified in the setup's install_requires.
All-in-one windows exe solutions such as py2exe or pyinstaller are not suitable since the entry point requires input, and I want the user to be able to specify the input via the command line.
Of course, I could distribute the module source files and have my coworkers run python setup.py install, but they will be too afraid - they are not programmers.

Yes, it would be possible to use an application like Nullsoft NSIS to build an installer that would install your python package, but it will require more code and an extra build step.
Do your coworkers have pip and setuptools installed? Are you able to distribute your package on pypi? If so, it would be really simple for your coworkers to just do pip install mypackage. It has the added benefit of handling dependencies and if you use python wheels, your users don't require a build environment to install your package.

What exactly does distutils do?

I have read the documentation but I don't understand.
Why do I have to use distutils to install python modules ?
Why do I just can't save the modules in python path ?

You don't have to use distutils. You can install modules manually, just like you can compile a C++ library manually (compile every implementation file, then link the .obj files) or install an application manually (compile, put into its own directory, add a shortcut for launching). It just gets tedious and error-prone, as every repetive task done manually.
Moreover, the manual steps I listed for the examples are pretty optimistic - often, you want to do more. For example, PyQt adds the .ui-to-.py-compiler to the path so you can invoke it via command line.
So you end up with a stack of work that could be automated. This alone is a good argument.
Also, the devs would have to write installing instructions. With distutils etc, you only have to specify what your project consists of (and fancy extras if and only if you need it) - for example, you don't need to tell it to put everything in a new folder in site-packages, because it already knows this.
So in the end, it's easier for developers and for users.

what python modules ? for installing python package if they exist in pypi you should do :
pip install <name_of_package>
if not, you should download them .tar.gz or what so ever and see if you find a setup.py and run it like this :
python setup.py install
or if you want to install it in development mode (you can change in package and see the result without installing it again ) :
python setup.py develop
this is the usual way to distribute python package (the setup.py); and this setup.py is the one that call disutils.
to summarize this distutils is a python package that help developer create a python package installer that will build and install a given package by just running the command setup.py install.
so basically what disutils does (i will sit only important stuff):
it search dependencies of the package (install dependencies automatically).
it copy the package modules in site-packages or just create a sym link if it's in develop mode
you can create an egg of you package.
it can also run test over your package.
you can use it to upload your package to pypi.
if you want more detail see this http://docs.python.org/library/distutils.html

You don't have to use distutils to get your own modules working on your own machine; saving them in your python path is sufficient.
When you decide to publish your modules for other people to use, distutils provides a standard way for them to install your modules on their machines. (The "dist" in "distutils" means distribution, as in distributing your software to others.)

using setuptools with post-install and python dependencies

This is somewhat related to this question. Let's say I have a package that I want to deploy via rpm because I need to do some file copying on post-install and I have some non-python dependencies I want to declare. But let's also say I have some python dependencies that are easily available in PyPI. It seems like if I just package as an egg, an unzip followed by python setup.py install will automatically take care of my python dependencies, at the expense of losing any post-install functionality and non-python dependencies.
Is there any recommended way of doing this? I suppose I could specify this in a pre-install script, but then I'm getting into information duplication and not really using setuptools for much of anything.
(My current setup involves passing install_requires = ['dependency_name'] to setup, which works for python setup.py bdist_egg and unzip my_package.egg; python my_package/setup.py install, but not for python setup.py bdist_rpm --post-install post-install.sh and rpm --install my_package.rpm.)

I think it would be best if your python dependencies were available as RPMs also, and declared as dependencies in the RPM. If they aren't available elsewhere, create them yourself, and put them in your yum repository.
Running PyPI installations as a side effect of RPM installation is evil, as it won't support proper uninstallation (i.e. uninstalling your RPM will remove your package, but leave the dependencies behind, with no proper removal procedure).