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How do I build a C Python Extension for Windows using Cygwin64?

To preface: my code works as I expect when compiling and running on Linux. However, this library needs to be compiled for use on a Windows machine. I looked in to a couple different options, and decided that using Cygwin to compile for Windows seemed to be the correct choice. I'm using a setup.py file with the distutils.core library and compiling using python setup.py install. When compiling on Windows in Cygwin, it fails to find pthread.h, arpa/inet.h, netinet/in.h, and sys/socket.h. I was under the impression that Cygwin came prepackaged with these headers, which is why I chose to use it. The alternative to Cygwin is putting preprocessor commands everywhere and using Windows specific libraries such as winsock2.h, which I want to avoid if at all possible. Is it possible to compile for Windows using Cygwin? If so, what have I done wrong to cause Cygwin to not recognize these headers?

You need to install the proper headers
$ cygcheck -p usr/include/pthread.h
Found 9 matches for usr/include/pthread.h
cygwin-devel-3.0.7-1 - cygwin-devel: Core development files
..
cygwin-devel-3.1.6-1 - cygwin-devel: Core development files
...
so install the cygwin-devel package
To check all the shared libraries needed by the built dll, you can use cygcheck
$ cygcheck /usr/lib/python3.8/site-packages/Cython/Compiler/FlowControl.cpython-38-x86_64-cygwin.dll
D:\cygwin64\lib\python3.8\site-packages\Cython\Compiler\FlowControl.cpython-38-x86_64-cygwin.
dll
D:\cygwin64\bin\cygwin1.dll
C:\WINDOWS\system32\KERNEL32.dll
C:\WINDOWS\system32\ntdll.dll
C:\WINDOWS\system32\KERNELBASE.dll
D:\cygwin64\bin\libpython3.8.dll
D:\cygwin64\bin\cygintl-8.dll
D:\cygwin64\bin\cygiconv-2.dll
D:\cygwin64\bin\cyggcc_s-seh-1.dll
As was built with Cygwin Python, you need also to transfer the cygwin python...

Most important, I think, is to follow the instructions in the Python help or on the Python doc web site for "Extending and Embedding the Python Interpreter" for the version you are building the extension for. For windows, the build instructions identify the build environment used to create the binary package that you download from python.org, usually something like VS2013 or VS2017. (As an aside, I think the Community editions have everything you need, and I don't think you actually have to use the Visual Studio GUI when you build using nmake from the CMD.EXE terminal.)
To build in Cygwin for use in a Windows version of Python, you may need to install and then use the x86_64-w64-mingw32-gcc, etc., cygwin packages to cross-compile non-cygwin (i.e. pure windows) executables and DLLs from Cygwin.
Binary extensions must be built using the source tree for a specific Python major.minor version, and bitness. For windows, you will need to build multiple versions of the extension, one for each major.minor, bitness version of Python that will import it, e.g. 3.6, 3.7, 3.8, 3.9, 32-bit, 64-bit. The extension code may not require changes between versions, but it still needs to be compiled with the right compiler and linked against exactly the same shared libraries (in this case .DLL files) as used by the Python executable. For instance, it must use exactly the same version of Microsoft's C run time library DLL as the Python executable does. This is a bit more sensitive and restrictive than on Linux, where you can rebuild the python executable and your extension with the same toolchain from your distro more easily.

Installing python package without a C++ compiler

I'm trying to get the HDBSCAN package to run on a Windows 7 machine with no C++ compiler. Installing a compiler is not an option, unfortunately.
I read that some packages have precompiled wheel files that require no compiler to install. The installation notes state "Binary wheels for a number of platforms are available thanks to the work of Ryan Helinski". However, there is no mention of where those can be found. My questions are then:
How do I obtain the .whl file for the HDBSCAN package?
Is it possible to simply compile+install on another machine and copy it? If so, what should the machine on which I compile have in common with the one on which the code must run? Can I do it on a Windows 10 machine, or does it have to be Win7 as well, do the same Windows updates need to have been run on both, etc?

Looks like there is no pre-built wheel distribution published by the maintainers of the project themselves on PyPI.
As already mentioned by other contributors, one could get such wheel distributions from a third party such as Christoph Gohlke's "Unofficial Windows Binaries for Python Extension Packages".
It is also of course possible to build such wheels yourself on one machine and then reuse it on another. As far as I know in the case of Windows, both machines need to have the same Python interpreter (minor) version as well as the same bitness (both 32 bits or both 64 bits). The exact version of the operating system should not matter (from Windows 10 to Windows 7 or the other way around should work).

I ended up getting this to work by compiling on another machine and copying the package from it. It was critical that the required packages were of the same version on both machines, so I simply set up a new conda environment which had the same package versions as the target machine, then intalled hdbscan with pip there, and copied.
I was worried about Windows version compatibility, but this worked even though I installed on Windows 10 and moved to a machine running Win7.

here is the site you can download the wheel file :https://www.lfd.uci.edu/~gohlke/pythonlibs/
for python 3.5>
or PyPi for older versions
run python -m pip install thefiledownloadedforyourpythonversion.whl
For the second question , yes you can but is rather complicated and you should avoid it when you can :)

I just checked. Python 3.8 is coded in C. You need a C compiler, not a C++ one. MINGW is one, and TinyCC Win32 is another one (a small one, producing quickly slow executables). Look also into this list of free C or C++ compilers.
A possibility (which could take several days of work) might be to use some WSL or some Linux emulator such as JSLinux (it runs in a web browser). Then you could (painfully) build a cross compiler (starting first with a tinycc-win32, then compiling an old cross GCC 3 compiler, then compiling with that a newer C++ GCC, etc....)
But the reality is that you should not be allowed to do this. Your real issue is non technical: why are you not allowed to install then use a C++ compiler, such as MinGW? Get permission (and resources) to install some....
Alternatively, consider installing some Linux distribution (ensure you are allowed to do so). Most of them have a recent Python and GCC...
Is it possible to simply compile+install on another machine and copy it?
This is called cross-compilation and is possible in general. The point is to be permitted to do that. You should find relevant cross-compilers for your situation.
If you are allowed to, you could even use a live Linux USB stick....
Some C compilers written in Python do exist.... You could use them to cross-compile tinycc for Win32. Then you should have a C compiler for Win32. You could then compile an old GCC, etc.... Qemu exist for windows. You could run a Linux with a cross-GCC compiler in Qemu.

Python compiler that can compile a program that utilises Pillow/PIL?

I've written a program that utilises the Pillow module (a PIL fork).
I would like to compile the finished program to an .exe for distribution.
I have tried compiling the program with both PyInstaller and Nuitka, however neither of these seem to support the compilation of a program that utilises this external module.
Does anyone know of any other Python compilers that support the compilation of a program that utilises the Pillow module?
Thank you

Installing Anaconda is your best bet.
Anaconda is a complete package of all python programming essentials. It also has your much needed pillow (or the so called python imaging library) built-in.
It comes with certain other python packages built-in and ready-to-use such as numpy, pandas, scipy, matplotlib, and IPython.
It also has an easy-to-use IDE namely Spyder, which is the playground. You get to do all your coding here. Spyder is just like any other text editor but with more functionality an ease of access.
If your looking out for more options in image processing, Anaconda also comes with scikit-image or skmage (also built-in)
In case you want to install OpenCV on your machine, it can be easily done using the Anaconda command prompt using this command:
conda install -c menpo opencv=3.0.0
Visit the website HERE

I decided to have another attempt at compiling my program using Pyinstaller.
Pyinstaller already worked with Pillow, however it ran into problems with programs that utilised Tix.
After a lot of trial and error, I managed to create a solution based on a comment on github.
My solution.

install natgrid in matplotlib in the environment of python 2.7

I'm quit new in using python. The current version I'm using is 2.7. I need to employ function mncontour in minuit which requires the installation of natgrid as additional toolkit for matplotlib. I downloaded natgrid 0.2.1 with a file named setup.py in it. I ran this setup.py through python shell without reaching any error. But it seems that the installation was not succeed. Anyone has any idea how the installation can be done? Many thanks.
Liang

Could you please provide some more information on this topic.
what operating system you are working with ( some offer more support than others for python)
have you installed python headers, and a C/C++ compiler in your environment? ( numerical libraries might require native code to speed up the computation)
Have you tried a package manager for python ( such as easy or pip)? Both work on both windows and unixes, and usually download and install all the needed packages to make your module working.
A piece of the setup's output before setup.py finished would help us help you greatly.
Python for Windows [Nt - 7] is compiled with either cygwin or mingw, thus you not only need the python environment, but also said compiler, and python headers. If you want a more point and click install, then there's this professor at this university who maintains a good and up to date repository of scientific python modules, that depend on native extensions ( among which numpy, scipy, matplotlib).
http://www.lfd.uci.edu/~gohlke/pythonlibs/
Manuals to setup mingw and python :
https://docs.python.org/2/using/windows.html
MingW can be downloaded from here:
http://www.mingw.org/

Best option for installing natgrid is from conda
conda install -c jochym natgrid=0.2

Python on AIX: What are my options?

I need to make some Python applications for a work project. The target platform is AIX 5.3.
My question is: What version of Python should I be using?
My requirements are:
The Python version must be easy to install on the target machines. Others will do that according to instructions that I write, so no compiling from source or anything like that.
The Python version must have ncurses or curses support (I'm making a form handler).
I've found two different precompiled versions of Python for AIX, but one (2.1.something) didn't include the curses module, and the other (2.3.4, RPM format) had prerequisites that I failed to fulfill).
Any help would be greatly appreciated.

Use the AS Package of Python 2.6.3.7 from Activestate. They have a binary package for AIX on their download site.
If you don't have an AIX machine to test it on, the install works the same way on Solaris or Linux, so you could write your documentation based on that. Basically, you ungzip the tarball file, use tar to unpack the archive, change directory to the unpacked folder, run a shell script to install it, tell the shell script what directory to place it in, and wait.
Normally this would be used to install into a user directory, without superuser permissions, but you could install it anywhere that you like. You might also need to edit the system profile in order to make sure that all users can find the Python binary.
I suggest the latest Python 2.6, because it has a lot of bugfixes, and there is now a critical mass of 3rd party libraries ported to it. Also, the standard library includes a lot of useful stuff that you used to have to collect separately. Curses is in the standard library of Python 2.6.
Make sure to avoid Python 3.1 since it has not yet matured enough and provides few benefits for most business applications development.

I'd compile it from source myself and tell them where to download it from in the instructions

We've used ActiveState's Python as well as Pware's compiled version. Both have worked well. For AS, we've used 2.5 and 2.6. For Pware, just 2.6. Both 2.5 and 2.6 from AS support curses on our machine.
I've compiled from source but usually wind up having trouble with with ctypes or SSL. Currently I have the Frankenstein option going of AS Python2.6 installed but I pulled out a couple of *.so files from Pware's. I'm using GCC since we've never ponied up for a compiler but depending on what you need from Python, it's definitely doable if I can do it.
I will mention that AS Python claims to be 100% compatible with standard Python and it has been for everything we've done so far (mostly web applications).