Environment variables#

HOME#

The user's home directory. On Linux,~ is shorthand forHOME.

MPLBACKEND#

This optional variable can be set to choose the Matplotlib backend. SeeWhat is a backend?.

MPLCONFIGDIR#

This is the directory used to store user customizations toMatplotlib, as well as some caches to improve performance. IfMPLCONFIGDIR is not defined,HOME/.config/matplotlibandHOME/.cache/matplotlib are used on Linux, andHOME/.matplotlib on other platforms, if they arewritable. Otherwise, the Python standard library'stempfile.gettempdir isused to find a base directory in which thematplotlib subdirectory iscreated.

PATH#

The list of directories searched to find executable programs.

PYTHONPATH#

The list of directories that are added to Python's standard search list whenimporting packages and modules.

QT_API#

The Python Qt wrapper to prefer when using Qt-based backends. Seetheentry in the usage guide for more information.

Setting environment variables in Linux and macOS#

To list the current value ofPYTHONPATH, which may be empty, try:

echo $PYTHONPATH

The procedure for setting environment variables in depends on what your defaultshell is. Common shells includebash andcsh. Youshould be able to determine which by running at the command prompt:

echo $SHELL

To create a new environment variable:

exportPYTHONPATH=~/Python# bash/kshsetenvPYTHONPATH~/Python# csh/tcsh

To prepend to an existing environment variable:

export PATH=~/bin:${PATH}  # bash/kshsetenv PATH ~/bin:${PATH}  # csh/tcsh

The search order may be important to you, do you want~/bin to besearched first or last? To append to an existing environment variable:

export PATH=${PATH}:~/bin  # bash/kshsetenv PATH ${PATH}:~/bin  # csh/tcsh

To make your changes available in the future, add the commands to your~/.bashrc or~/.cshrc file.

Setting environment variables in Windows#

Open theControl Panel (Start ‣ Control Panel),start theSystem program. Click theAdvanced taband select theEnvironment Variables button. You can edit or add totheUser Variables.