Support trailing commas?

[meliache]

In some codebases I have seen that trailing commas are used in function definitions, especially when functions take a lot of keyword parameters and people frequently change or add them. Trailing commas then help with version control and guard against forgotten commas. You might argue whether this is good stile, but the following is valid python:

def foo(arg1, arg2, arg3,):
    return bar

sphinx-doc then fails, because sphinx-doc-fun-args creates an empy string "" as the last arg. I fixed that in place by just removing empty strings from the argument list with remove "". But maybe there is a better place to implement a fix. I didn't go really went into understanding your code, so I refrained from a PR.

(defun sphinx-doc-fun-args (argstrs)
  "Extract list of arg objects from string ARGSTRS.
ARGSTRS is the string representing function definition in Python.
Note that the arguments self, *args and **kwargs are ignored."
  (when (not (string= argstrs ""))
    (mapcar #'sphinx-doc-str->arg
            (-filter
             (lambda (str)
               (and (not (string= (substring str 0 1) "*"))
                    (not (string= str "self"))))
             (remove ""
              (mapcar #'s-trim
                      (split-string argstrs ",")))))))

[naiquevin]

It's a small change so I don't mind merging it. But I think only the last empty arg should be stripped and not all empty args. eg.

   def foo(a, b, , c): 
       pass

Is invalid python and sphinx-doc should not handle this case.

[kbeismann]

The fix in #22 covers both cases.