Differences in the reported value of the Provides field in apt-cache

[aprekates <aprekates@posteo.net>]

I noticed the following difference in the reported
'Provides' value.

$ sudo apt-cache show python3
Package: python3
....
Provides: python3-profiler

$ sudo apt-cache showpkg python3
...
Provides:
3.5.3-1 - python3-profiler:i386 (= ) python3:any (= 3.5.3-1) 
python3-profiler (= ) python3-profiler:any (= )

I cant make sense of all those 'virtual' packages:
python3-profiler:i386 (= ) python3:any (= 3.5.3-1) python3-profiler (= ) 
python3-profiler:any (= )

The control file of python3_3.5.3-1_amd64.deb outputs only:
Provides: python3-profiler

Obviously those 'produced' Provides values declare sth related to 
architectures.But i dont
understand the logic.

We have a package : Architecture: amd64
That package provides python3:any ?  It'd made more sense to me to 
provide python3:amd64 , assuming
that there are other packages providing 'python3' 'functionality'.

Also i think that there is not other package 'providing' python3. So i 
cant understand why even that virtual package exists (if we assume that 
showpkg reports is also true).

Alexandros.