The C implementations should follow the kernel/git coding style.
Python code follows PEP8 with regard to coding style and PEP257 with regard to docstring style. Multi-line docstrings should have one short summary line, followed by a blank line and a series of paragraphs. The last paragraph should be followed by a line that closes the docstring (no blank line in between). Here's an example from lib/bup/helpers.py
:
def unlink(f):
"""Delete a file at path 'f' if it currently exists.
Unlike os.unlink(), does not throw an exception if the file didn't already
exist.
"""
...
Module-level docstrings follow exactly the same guidelines but without the blank line between the summary and the details.