Renzeee Renzeee - 4 months ago 40
Python Question

Installing NumPy and SciPy on 64-bit Windows (with Pip)

I found out that it's impossible to install NumPy/SciPy via installers on Windows 64-bit, that's only possible on 32-bit. Because I need more memory than a 32-bit installation gives me, I need the 64-bit version of everything.

I tried to install everything via Pip and most things worked. But when I came to SciPy, it complained about missing a Fortran compiler. I installed it via MinGW/MSYS. But you can't install SciPy right away after that, you need to reinstall NumPy. So I tried that, but now it doesn't work anymore via Pip nor via easy_install. Both give these errors:

  • There are a lot of errors about

  • I get a lot of errors in the range of
    C2143`, etc. They belong together I believe.

  • There is no Fortran linker found, but I have no idea how to install that, can't find anything on it.

  • And many more errors which are already out of the visible part of my cmd-windows...

  • The fatal error is about

    build\\numpy\linalg\lapack_lite.pyd : fatal error LNK1120: 7 unresolved externals
    error: Setup script exited with error: Command "C:\Users\me\AppData\Local\Programs\Common\Microsoft\Visual C++ for Python\9.0\VC\Bin\amd64\link.exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:C:\BLAS /LIBPATH:C:\Python27\libs /LIBPATH:C:\Python27\PCbuild\amd64 /LIBPATH:build\ lapack.lib blas.lib /EXPORT:initlapack_lite build\\Release\numpy\linalg\lapack_litemodule.obj /OUT:build\\numpy\linalg\lapack_lite.pyd /IMPLIB:build\\Release\numpy\linalg\lapack_lite.lib /MANIFESTFILE:build\\Release\numpy\linalg\lapack_lite.pyd.manifest" failed with exit status 1120

What is the correct way to install the 64-bit versions NumPy and SciPy on a 64-bit Windows machine? Did I miss anything? Do I need to specify something somewhere? There is no information for Windows on these problems that I can find, only for Linux or Mac OS X, but they don't help me as I can't use their commands.


Numpy (as also some other packages like Scipy, Pandas etc.) includes lot's of C-, Cython, and Fortran code that needs to be compiled properly, before you can use it. This is, btw, also the reason why these Python-packages provide such fast Linear Algebra.

To get precompiled packages for Windows, have a look at Gohlke's Unofficial Windows Binaries or use a distribution like Winpython (just works) or Anaconda (more complex) which provide an entire preconfigured environment with lots of packages from the scientific python stack.