Building NumPy on RedHat - python

I installed a local version of Python 2.7 in my home directory (Linux RedHat) under ~/opt using the --prefix flag.
More specifically, Python was placed in ~/home/opt/bin.
Now, I want to install NumPy, but I am not really sure how I would achieve this. All I found in the INSTALL.txt and online documentation was the command to use the compiler.
I tried gfortran, and it worked without any error message:
python setup.py build --fcompiler=gnu95
However, I am not sure how to install it for my local version of Python.
Also, I have to admit that I don't really understand how this whole approach works in general. E.g., what is the setup.py build doing? Is it creating module files that I have to move to a specific folder?
I hope anyone can give me some help here, and I would also appreciate a few lines of information how this approach works, or maybe some resources where I can read it up (I didn't find anything on the NumPy pages).

Your local version of python should keep all of it's files somewhere in ~/opt (presumably). As long as this is the python installation that gets used when you issue the command
python setup.py build --fcompiler=gnu95
you should be all set because in the sys module, there are a bunch of constants which the setup script uses to determine where to put the modules once they are built.
So -- running python setup.py build issues all of the necessary commands to build the module (compiling the C/Fortran code into shared object libraries that python can load dynamically and copying the pure python code to create the proper directory structure). The module is actually built somewhere in the build subdirectory which gets created during the process if it doesn't already exist. Once the library has been built (successfully), installing it should be as simple as:
python setup.py install
(You might need to sudo if you don't have write privileges in the install directory).

Related

How to install python modules using cppyy?

I want to package a python module containing python source and a native c++ library. Cppyy is used to dynamically generate the bindings so the library is really just a normal library. The build system for the library is meson and should not be replaced. The whole thing is in a git repository. I only care about Linux.
My question is how to get from this to “pip install url_to_package builds/installs everything.” in the least complicated way possible.
What I’ve tried:
Extending setuptools with a custom build command:
…that executes meson compile and copies the result in the right place. But pip install will perform its work in some random split-off temporary directory and I can’t find my C++ sources from there.
The Meson python module:
…can build my library and install files directly into some python env. Does not work with pip and has very limited functionality.
Wheels:
…are incredibly confusing and overkill for me. I will likely be the only user of this module. Actually, all I want is to easily use the module in projects that live in different directories…
Along the way, I also came across different CMake solutions, but those are disqualified because of my build system choice. What should I do?

Getting OpenCV to work with python after compiling from source

I am having an issue getting OpenCV to work with python. I compiled from source using CMake in order to gain access to the SIFT module. Whenever I try to use openCV however, python returns the "No module named 'cv2'" error. It works fine when I install using pip but then I have no SIFT. My build directory is set as an environment variable and my bin directory is in my system path. There were no build issues and the applications that came with the build run fine. Is there another step that I have to perform, such as installing from the compiled project using pip? How do I get my openCV library, compiled from source, to be importable by python?
The solution ended up being both simpler and sloppier than I would have liked. I just installed the regular distribution using pip install opencv-contrib-python, then went into the cv2 folder in Lib/site-packages, replaced the python extension (cv2.cp36-win32.pyd in my case. may be different for others) with the .pyd file from my CMake build (build/lib/python3/Release) and copied everything from build/bin/Release into the Lib/site-packages/cv2 folder. It doesn't look pretty or organized but python can find everything now. If anyone has a cleaner way to do this I'd love to hear it.

Specifying installation path of python modules from installed RPM

I have a simple python script that I have been trying to package into an RPM. This was a simple python script that you can run by calling "./". However, to package it into an RPM, I turned the script into a module with a init.py and setup.py. I was able to package it into an rpm using "python setup.py bdist_rpm" following https://docs.python.org/2.0/dist/creating-rpms.html . I was also able to install the created .noarch.rpm file into a different machine. However, I have no idea how to use this script now after I installed the .noarch.rpm file.
So, I successfully installed the .noarch.rpm file that has my script packaged into it, but I have no idea where this file is or how to use my script from this. This is my very first time creating an RPM, and I am fairly new to Python as well, so I think I am just missing something. Is there a way to specify where the python module is installed when I install the .noarch.rpm?
I am running on RHEL. I also looked at two other StackExchange questions/answers that are similar to what I want, but I still do not quite understand what to do. Here are the other questions/answers: Python distutils - Change Path RPM Installs To and Creating Python RPM
You can get list of files in your RPM package by:
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Building PyCrypto with fastmath (gmp or mpir) via pip on Windows

I installed PyCrypto on Windows via pip but i was not able to build Crypto.PublicKey._fastmath because GMP was not found.
I know there is a binary version on voidspace but i would like to build the latest version of PyCrypto
The following one is a way to achieve your goal. There are other, probably better ways (e.g. based on Visual Studio), but this one has worked for me. Additionally, it does not use pip.
All operations are carried out on a command prompt.
Install Mingw, including MSYS and the Development Toolkit. This will give you a fairly complete Unix-like development environment.
Ensure that Mingw binaries are in PATH environment variable. You need MinGW\bin and MingGW\msys\1.0\bin.
Download MPIR sources in a temporary directory. It is important you do not use 2.5.1 because of a bug that will break the build. 2.5.0 is fine.
Build the MPIR library. This is fairly straightforward: execute bash configure followed by make.
HACK #1 Copy libmpir.a from mpir-2.5.0\.libs into C:\Python2.7.1\libs. This is necessary because distutils is broken and I could not find a way to direct it to the correct library location.
HACK #2 Edit C:\Python2.7.1\Lib\distutils\cygwincompiler.py and remove any occurrance of the string -mno-cygwin. The reason is explained here.
Download PyCrypto sources and unpack them in another temporary directory.
Set CPPFLAGS environment variable to the MPIR directory, which contains mpir.h.
HACK 3 Edit setup.py and add the following line in build_extension method:
self.__add_compiler_option(os.environ['CPPFLAGS'])
Run bash configure. You should see two lines saying:
checking for __gmpz_init in -lgmp... no
checking for __gmpz_init in -lmpir... yes
Execute python setup.py build -c mingw32. You should see no errors.
Execute python setup.py test to verify that everything is fine.
Execute python setup.py install to copy the files into your local Python repository.
Alternatively, run python setup.py bdist_wininst to create an installer.
I really hate all the various hacks, and I'd love to hear if they can be avoided.

Make an installer for python project

I downloaded an open source project http://gmapcatcher.googlecode.com/files/GMapCatcher-0.7.2.0.tar.gz and I am trying to modify a few things in the code but don't know how to test the code!
I tried to make an installer for the project but nothing worked till now maybe I didn't follow the right steps or I am missing somthing.
my question is how can I modify the code and test it ? and how can I make an installer for this project (I know there is an installer already in google but I want to make it myself).
Looks like the package has a setup.py for the use with distutils. The setup.py works kind of like Makefile for python. The way you use it is (in the directory where setup.py is located:
$ python setup.py command
Where "command" is... well... a command. Type
$ python setup.py --help
for more information. The two basic commands are build and install. install installs, as the name suggests, the package to your system. It is not probably going to do anything like create shortcuts on your desktop or anything like that. It simply installs the Python package into your Python installation. Judging by the contents of setup.py, it seems they're somehow using py2exe (google it; being a newbie I can only include one hyperlink in my answer) to prepare the Windows installer.
To simply run the software, however, it seems all you need to do is to unpack it and do
$ python maps.py
in the package's root directory - provided you have all the necessary dependencies already installed, of course.

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