git-log

Showing HEAD commit logs

Show HEAD commit

$ git log -1

>>> commit = repo[repo.head.target]
>>> commit.message
'commit message'

Traverse commit history

$ git log

>>> last = repo[repo.head.target]
>>> for commit in repo.walk(last.id, pygit2.enums.SortMode.TIME):
>>>     print(commit.message) # or some other operation

Show trailers from the last commit

$ git log --format='%(trailers:key=Bug)'

>>> last = repo[repo.head.target]
>>> for commit in repo.walk(last.id, pygit2.enums.SortMode.TIME):
>>>     print(commit.message_trailers.get('Bug'))

References

git-log.
libgit2 discussion about walker behavior. Note that the libgit2’s walker functions differently than git-log in some ways.