Windows Installation

The SpacePy team currently provides binary “wheels” via PyPI so it can be installed on Windows without a compiler. Binaries are provided for Python 2.7 and 3.6 through 3.9 in 64-bit and 32-bit variants for each. pip install spacepy should find and install these binaries.

At this writing (2020-12-24), a Windows bug affects numpy. Version 1.19.3 is known to work, so it is strongly recommended to install this version:

  1. pip install numpy==1.19.3

  2. pip install spacepy

The bug is documented here. It will affect users for whom all of the following are true. In general, if you don’t know, the answer is probably yes:

  1. Running 64-bit Windows

  2. Running the latest (2004) update of Windows 10.

  3. Not taking specific action to compile numpy and its dependent libraries in a way that works around this bug.

32-bit Windows binaries will be discontinued with SpacePy 0.3, so installing 32-bit SpacePy will require compiling.

Our recommended (but not required) Python distribution is Anaconda running 64-bit Python 3. Anaconda includes much of the scientific Python stack. Another excellent distribution is Canopy.

You may need to install the dependencies some way other than pip; for example, if you are running an earlier version of Python. The latest version of many dependencies requires Python 3.6 and pip will not install older versions to get around this. See Dependencies via conda.

Fortran and ffnet

ffnet is required for LANLstar. It can be installed either before or after SpacePy. Binary wheels are not provided, so a Fortran compiler is required.

With Anaconda, the compiler and ffnet can be installed with:

conda install m2w64-gcc-fortran libpython
SET FC_VENDOR=gfortran
pip install ffnet

The FC_VENDOR line is necessary because ffnet defaults to the Microsoft compiler.

Some standalone binary installers (no pip support) are also available on the ffnet site. These do not require a compiler but support only a limited set of Python versions.


If a binary wheel is not available for your version of Python, pip will try to compile SpacePy. The only supported compiler is mingw32. Install it with:

conda install m2w64-gcc-fortran libpython

This is also required if installing from a source distribution or git checkout.

irbempy requires Fortran to compile and the only supported compiler is gnu95; this is the default and provided by m2w64-gcc-fortran.

If you have difficulties, it may be useful to reference the build scripts the SpacePy developers use.


pycdf requires the NASA CDF library . Binary installers are available for Windows; be sure to pick the version that matches your Python installation. The current 32-bit version is cdf37_1_0-setup-32.exe; for 64-bit, cdf37_1_0-setup-64.exe.

This is a simple self-extracting installer that can be installed either before or after installing SpacePy.

Standalone installers

Standalone installers for Windows will be discontinued starting with SpacePy 0.3. Binary wheels will still be provided and can be downloaded from the same location and installed with pip, e.g. pip install spacepy-0.2.2-cp38-cp38-win_amd64.whl.

Self-extracting and self-installing executables are also available for download direct from our github. Be sure to choose the file that matches your Python installation, both in Python version and word size (64-bit vs. 32-bit.) E.g. is the installer for Python 3.6 on 64-bit Windows and spacepy-0.2.0.win32.py27.exe is the installer for Python 2.7 on 32-bit Windows.

Once downloaded, these can be installed without an internet connection.

If using these installers, the SpacePy Dependencies will not be installed automatically.

Dependencies via conda

Installation via pip will automatically install most Python dependencies (but not ffnet or the NASA CDF library). They can also be installed from conda:

conda install numpy scipy matplotlib networkx h5py

Standalone dependencies

Most of the SpacePy Dependencies have Windows installers available via their pages, but pip or conda are recommended instead.


If you want to build the documentation yourself (rather than using the documentation shipped with SpacePy), install sphinx and numpydoc. The easiest way is via pip:

pip install sphinx numpydoc

They are also available via conda:

conda install sphinx numpydoc