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Error installing PyMVPA2

I'm getting the following error when I try to install using pip install for PyMVPA2 for Python. I have installed other libraries without any problems before. I would appreciate if anything could take a look at the errors:
C:\Users\usr>pip install pymvpa2
Collecting pymvpa2
Using cached pymvpa2-2.4.2.tar.gz
Complete output from command python setup.py egg_info:
running egg_info
running build_src
build_src
building extension "mvpa2.clfs.libsmlrc.smlrc" sources
building extension "mvpa2.clfs.libsvmc._svmc" sources
creating build
creating build\src.win32-2.7
creating build\src.win32-2.7\mvpa2
creating build\src.win32-2.7\mvpa2\clfs
creating build\src.win32-2.7\mvpa2\clfs\libsvmc
swig.exe++: mvpa2\clfs\libsvmc\svmc.i
swig.exe -python -I3rd\libsvm -c++ -I3rd\libsvm -o build\src.win32- 2.7\mvpa2\clfs\libsvmc\svmc_wrap.cpp -outdir build\src.win32-2.7\mvpa2\clfs\libsvmc mvpa2\clfs\libsvmc\svmc.i
error: command 'swig.exe' failed: No such file or directory
----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in c:\users\usr\appdata\local\temp\pip-build-v_zzkd\pymvpa2\

As the error states you either don't have swig installed or it is not on your path. You are obviously on Windows so you need to download the swig executable from the swig website - download the latest windows package and either unzip it to a directory on your existing path or to a new directory and add it to your path. Easiest, of course, is to unzip it to a new directory and then run your pip command in that directory.
What is swig anyway? Swig parses the interface definitions of code written in C/C++ and can output 'glue code' to allow code written in Python & a pile, currently 22, of other programming or scripting languages to use the C/C++ code transparently. Swig is free, open source and compatible with both open source and commercial use.
Should I keep it to hand? In most cases that I know of in python swig is only invoked during the installation or setup phase but since that setup phase will be used every time that any package built with swig is installed or upgraded there is no reason to get rid of it and quite a lot of reasons to have it somewhere on your path.

sudo apt-get remove swig
sudo apt-get install swig3.0
sudo ln -s /usr/bin/swig3.0 /usr/bin/swig
and then
pip install pymvpa2

installing pyside using PIP - nmake not found

I want to install PySide using PIP package manager. But it get this error message saying it didn't find nmake. This is no surprise because I do not have MSVC installed nor do I intend to.
Installing collected packages: pyside
Running setup.py install for pyside
Removing c:\users\cnyffele\appdata\local\temp\pip_build_cnyffele\pyside\pyside_package
Python architecture is 32bit
nmake not found. Trying to initialize the MSVC env...
Searching MSVC compiler version 9.0
error: Failed to find the MSVC compiler version 9.0 on your system.
However the setup.py program could simply run make:
C:\Users\cnyffele>where make
C:\MinGW32-xy\bin\make.exe
C:\Users\cnyffele>where mingw32-make
C:\MinGW32-xy\bin\mingw32-make.exe
But for some reason, it insists that if the platform is "win32" it should use msvc without trying anything else. It does, however, accept command-line options: I could specify "make-spec" to be "mingw" (see below).
From https://github.com/PySide/pyside-setup/blob/master/setup.py
OPTION_MAKESPEC = option_value("make-spec")
...
if sys.platform == "win32":
if OPTION_MAKESPEC is None:
OPTION_MAKESPEC = "msvc"
if not OPTION_MAKESPEC in ["msvc", "mingw"]:
print("Invalid option --make-spec. Available values are %s" % (["msvc", "mingw"]))
sys.exit(1)
How can I make setyp.py use the correct make when installing with PIP? Is there a way to have PIP provide command-line options to setup.py when it runs it? If this is not possible, how can I run setup.py manually after PIP downloaded it?

PIP allows passing options to setup via the options '--global-option' and '--install-option' as described in the pip reference guide.
The solution is:
pip install --global-option="--make-spec=mingw" PySide
Some additional information:
That prior to installing PySide using pip, you have to install cmake and Qt 4.8.
Build errors prevented me from downloading and installing PySide directly via pip. I needed to download the wheel binary packages from pypi.python.org.
Using a pre-downloaded .whl package, assuming the package is located in the current working directory:
pip install --global-option="--make-spec=mingw" PySide-1.2.4-cp27-none-win32.whl

Force compiler when running python setup.py install

Is there a way to explicitly force the compiler for building Cython extensions when running python setup.py install? Where setup.py is of the form:
import os.path
import numpy as np
from setuptools import setup, find_packages, Extension
from Cython.Distutils import build_ext
setup(name='test',
packages=find_packages(),
cmdclass={'build_ext': build_ext},
ext_modules = [ Extension("test.func", ["test/func.pyx"]) ],
include_dirs=[np.get_include()]
)
I'm trying to install a package on Windows 8.1 x64 using Anaconda 3.16, Python 3.4, setuptools 18, NumPy 1.9 and Cython 0.24. The deployment script is adapted from the Cython wiki and this Stack Overflow answer:
Makefile.bat
:: create and activate a virtual environement with conda
conda create --yes -n test_env cython setuptools=18 pywin32 libpython numpy=1.9 python=3
call activate test_env
:: activate the MS SDK compiler as explained in the Cython wiki
cd C:\Program Files\Microsoft SDKs\Windows\v7.1\
set MSSdk=1
set DISTUTILS_USE_SDK=1
#call .\Bin\SetEnv /x64 /release
cd C:\test
python setup.py install
The problem is that in this case setup.py install still used the MinGW compiler included with conda instead of the MS Windows SDK 7.1 one.
So the DISTUTILS_USE_SDK=1 and MSSdk=1 don't seem to have an impact on the build. I'm not sure if activating the MS SDK from within a conda virtualenv might be an issue here.
Running python setup.py build_ext --compiler=msvc correctly builds the extension with the MS compiler, but subsequently running the setup.py install recompiles it with MinGW again. Same applies to python setup.py build --compiler=msvc.
Also tried running %COMSPEC% /E:ON /V:ON /K "%PROGRAMFILES%\Microsoft SDKs\Windows\v7.1\Bin\SetEnv.cmd" as discussed in the answer linked above, but for me this produces a new terminal prompt, colored in yellow, and stops the install process.
Is there a way of forcing the compiler for building this package, for instance, by editing the setup.py?

You can provide (default) command line arguments for distutils in a separate file called setup.cfg (placed parallel to your setup.py). See the docs for more information. To set the compiler use something like:
[build]
compiler=msvc
Now calling python setup.py build is equivalent to calling python setup.py build --compiler=msvc. (You can still direct distutils to use an other complier by calling python setup.py build --compiler=someothercompiler)
Now you have (successfully directed distutils to use a msvc compiler. Unfortunately there is no option to tell it which msvc compiler to use. Basically there are two options:
One: Do nothing and distutils will try to locate vcvarsall.bat and use that to setup an environment. vcvarsall.bat (and the compiler it sets the environment up for) are part of Visual Studio, so you have to have installed that for it to work.
Two: Install the Windows SDK and tell distutils to use that. Be aware that the name DISUTILS_USE_SDK is rather missleading (at least in my opinion). It does NOT in fact tell distutils to use the SDK (and it's setenv.bat) to setup an environment, rather it means that distutils should assume the environment has already been set up. That is why you have to use some kind of Makefile.bat as you have shown in the OP.
Side Note: The specific version of VisualStudio or the Windows SDK depends on the targeted python version.

As a remark: on linux, you can use many of the autoconf environment variables. For the compiler
CC=mpicc python setup.py build_ext -i

Well I found a trick in my case : I wanted to use MSVC14.0 (from buildtools 2015) and NOT MSVC14.1 (buildtools 2017). I edited the file Lib\distutils_msvccompiler.py. There is a method
_find_vcvarsall
which is calling
best_version, best_dir = _find_vc2017()
I replaced this call by
best_version, best_dir = _find_vc2015()
Do not forget to undo this dirty trick once compiled.

I ended up putting this at the beginning of setup.py to force visual2015
useful when running in a non bat environment and starting vcvarsall from outside is not an option
if sys.platform == 'win32':
# patch env with vcvarsall.bat from vs2015 (vc14)
try:
cmd = '"{}..\\..\\VC\\vcvarsall.bat" x86_amd64 >nul 2>&1 && set'.format(environ['VS140COMNTOOLS'])
out = subprocess.check_output(cmd, stderr=subprocess.STDOUT, universal_newlines=True)
except:
print("Error executing {}".format(cmd))
raise
for key, _, value in (line.partition('=') for line in out.splitlines()):
if key and value:
os.environ[key] = value
# inform setuptools that the env is already set
os.environ['DISTUTILS_USE_SDK'] = '1'

There is a --skip-build option of install command which will help you with this. You can also specify multiple commands in a row, like so:
python setup.py build --compiler=msvc install --skip-build
Here is a list of supported compiler types (as returned by setup.py build_ext --help-compiler):
--compiler=bcpp Borland C++ Compiler
--compiler=cygwin Cygwin port of GNU C Compiler for Win32
--compiler=mingw32 Mingw32 port of GNU C Compiler for Win32
--compiler=msvc Microsoft Visual C++
--compiler=unix standard UNIX-style compiler
Note: To prevent compati­bi­lity issues extension modules should be built with the same compiler as the Python interpreter itself.

Python-Asurv Installation

When I try to install python-asurv using setup.py, (typing "path"\python "path"\setup.py install in the command prompt), I get the following error:
building extension "twokm" sources target build\src.win32-2.7\twokmmodule.c does not exist: Assuming twokmmodule.c was generated with "build_src --inplace" command. error: '.\\twokmmodule.c' missing`
I am on windows 7 64bit with 32bit python2.7
In the zip file that I downloaded, there is setup.py, asurv.py, asurv.pyc, two licences, a readme, and twokm.pyf and twokm.f, which I think are in fortran format (don't know anything about fortran). The README just says type python setup.py install.
I think that for the twokm.pyf and twokm.f files I need to use f2py to convert them to .py files, am I right?
How can I install python-asurv?

Make sure you have installed numpy at it is dependency of python-asurv
Do pip install numpy and then Do python setup.py install in the directory you have downloaded.

Python: Unable to easy_install (Windows 7 x64)

I'm running python 2.7 on Windows 7 x64, and trying to easy_install pysqlite.
With command: easy_install -U pysqlite
It exits with the error:
error: Setup script exited with error: Unable to find vcvarsall.bat
This site: http://code.google.com/p/rdflib/issues/detail?id=104#c4
suggests a workaround of installing MingGW, saying to check the g++ option on install (plus some other stuff).
Unfortunately, MingGW does not give me the option to install g++, only c++, and of course on running easy_install a second time, I get ".. command 'gcc' failed: No such file or directory". So now I am el stucko.
Any advice on how to fix this problem would be great!

Even if you install a compiler (MinGW or Visual Studio), you still have to install SQLite3 development libraries. It is a pain to build things on Windows, so I suggest that you get the unofficial pre-built Windows binaries and install it.
As an aside, you should probably consider switching to ActivePython as it includes a package manager that allows you to install pre-built modules from ActiveState's repository.
As for the particular error in question, that is a distutils bug and you should raise your concerns in the Python bug tracker.

When that says "g++ compiler" they really mean the C++ compiler, which for mingw is gcc.

You need to install the Microsoft Visual C compiler thingy (the 2010 one). And use that as your compiler for all modules. You can also mess with distuls.cfg and specify a compiler that way.