Install libpython3.6-testsuite by entering the following commands in the terminal:
sudo apt update sudo apt install libpython3.6-testsuite
Testsuite for the Python standard library (v3.6)
The complete testsuite for the Python standard library. Note that a subset is found in the libpython3.6-stdlib package, which should be enough for other packages to use (please do not build-depend on this package, but file a bug report to include additional testsuite files in the libpython3.6-stdlib package).