Vim plugin to toggle Python function/method arguments between single- and multi-line -

i'm looking vim plugin can take single-line statement this:

foo = self.some_method(param1="hi", param2="there") 

and turn this:

foo = self.some_method(     param1="hi",     param2="there" ) 

big bonus points if can append comma last argument, this:

foo = self.some_method(     param1="hi",     param2="there", ) 

and i'd able turn multi-line version single line, handling single-to-multi-line scenario alone sufficient me. using j re-join line fast enough of time.

i'm not looking solution formats this:

foo = self.some_method(param1="hi",                        param2="there") 

with plugin: splitjoin.vim. using example can like:

foo = self.some_method(param1="hi", param2="there", param3="again") 

with cursor between parenthesis, invoke using default maping gs :

foo = self.some_method(param1="hi",         param2="there",         param3="again") 

to return original gj

it work many languages. python can split dicts, lists, tuples, statements, imports