Thanks for reply. I could integrate PEPY into my GUI for pip, called
pips.
As you can see on the first screenshot, PIPS shows some package info in
the tooltip. Since download stats had been removed from PyPi, PIPS haven't had
any simple provider for that, and here PEPY came out.
Another use is sorting search results by download rate, thus, most
popular packages have to be shown at the beginning of the install suggestions list (second screenshot).
There're some other PyPi stats tools, like
pypi-cli which I guess are
broken now and could switch to a new API as well.