In order to make PyDM a flexible tool a couple of Environment Variables are used for configuration and customization.

The following table describe the environment variable as well as its usage and default values.


What is it used for?


The default protocol to be used when specifing channels.
This option eliminates the need for users to specify the protocol
for a given Data Plugin. E.g.: ca.
Default: None


This variable point to the base URL for the documentation.


This is the base URL for the Archiver Appliance Data Plugin it is
concatenated with /retrieval/data/getData to generate the
retrieval URL.


Which library to use for Channel Access (ca://) data
plugin. PyDM offers two options: PYCA and PYEPICS.
Default: PYEPICS


Path to pydm executable for child processes, such as new windows.
It will only be used if pydm is not found in the standard $PATH.
Default: None


Path(s) in which PyDM should look for .ui, .py, and .adl files when
they are not found. If more than one path is specified, separate with
: on linux or ; on Windows.
Note: This is not a recursive search.
Default: None


Path in which PyDM should look for Data Plugins to be loaded.
Default: None


Path in which PyDM should look for External Tools to be loaded.
Default: None


Path to a PyDM display file to use as the home display in the navigation bar.
Will be returned to when the user clicks on the home button. If not set, the
first display opened will be used as the home display. If the command line option
--homefile is set, that will take precedence over this environment variable.


The string encoding to be used when converting arrays to strings.
Default: utf-8


Path to the QSS files defining the global stylesheets for the
PyDM application. When used, it will override the default look.
If using multiple files they must be separated by the path separator.
Only files are supported, not directories. On this list, like a PATH
variable, the first elements will take precedence over others.
E.g.: /path_to/my_style_1.qss:/path_to/other/my_other_style.qss
Default: None


Whether or not to include the PyDM Default stylesheet along with customized
files. Note that the PyDM default stylesheet will have lower precedence compared
to files specified at PYDM_STYLESHEET
Default: False


This flag enables receiving live data in Qt Designer. If disabled,
channels will not be connected to in Qt Designer.
Default: None