Make partial out from a function.

_partial.py

def _partial(func, *args, **keywords):
    @wraps(func)  # functools.wraps doesn't wrap func, so add it here
    def newfunc(*fargs, **fkeywords):
      newkeywords = {**keywords, **fkeywords}
      return func(*args, *fargs, **newkeywords)
    newfunc.func = func
    newfunc.args = args
    newfunc.keywords = keywords
    return newfunc