zipped VTK files

Is Paraview able to read a zipped ascii VTK file – e.g. “results.vtk.gz”?
If not, would a reader plugin be able to enable it?

No, not possible by default.

Yes, possible with a plugin.

Thanks.
One more question: to write a plugin, I need the Paraview source code, and write the plugin in C++/xml, right? Or can I code it in Python?

Both are possible

This is great news for me, because I read below that “VTK is written in C++, and new readers should also be written in this language.”:

https://www.paraview.org/Wiki/Writing_ParaView_Readers

I would highly appreciate if you point me to any example of a file reader using python.

This is an old documentation, see this:
https://gitlab.kitware.com/paraview/paraview/blob/master/Examples/Plugins/PythonAlgorithm/PythonAlgorithmExamples.py

Thank you!