Pygit2 is a set of Python bindings to the libgit2 shared library, which implements the Git core methods. Unfortunately, it only seems to provide an API towards plumbing commands.
Is there any python library built on the top of pygit2 which provides an implementation of the most common git porcelain commands?
The plumbing commands are those which are only expected to interact with a user and as such their output is subject to change at any time and have a granularity which as a rule is not particularly useful for a computer programme.
If you're not interested in the data structures from libgit2, but rather want to run pluming commands for scripting, you might want to take a look at GitPython which wraps git's own commands behind a python API.