tkinter is intended to be optional, but actually is required through the default import of the viewer.
A small adjustment on the pattern used in this commit could ensure no attempt to actually import pds4_tools.viewer.core is made at all until the user tries to call the viewer. However this breaks the docstring recognition for pds4_viewer by pycharm and I suspect most other IDEs. Therefore I am sticking with the slightly different approach used here.
tkinter is intended to be optional, but actually is required through the default import of the viewer.
A small adjustment on the pattern used in this commit could ensure no attempt to actually import
pds4_tools.viewer.coreis made at all until the user tries to call the viewer. However this breaks the docstring recognition forpds4_viewerby pycharm and I suspect most other IDEs. Therefore I am sticking with the slightly different approach used here.