Add a command for managing pip's cache

[pradyunsg]

pip's cache is currently a black box that the users can't really inspect. This is not the nicest of experiences. Adding a pip cache to allow interacting with the cache (much like the new pip config) would be a good way to fix that.

Here's a proposal for the same:

$ pip cache --help
Usage:
  pip cache info
  pip cache list [name]
  pip cache purge [name/pattern]

Description:
  Manage what packages are available in pip's caches.

PS: This is the same idea as pip cache as expressed in #3968 and #3734. I'm just creating a tracking issue for it since both the PR authors seem to have lost interest and having an open issue for tracking a new feature seems cleaner to me.

[Jamim]

Hi there,
Does anyone work on this?

[pradyunsg]

No one yet, AFAIK.