split string at commas respecting quotes when string not in csv format

[Terry Reedy]

R. David Murray wrote:
> OK, I've got a little problem that I'd like to ask the assembled minds
> for help with.  I can write code to parse this, but I'm thinking it may
> be possible to do it with regexes.  My regex foo isn't that good, so if
> anyone is willing to help (or offer an alternate parsing suggestion)
> I would be greatful.  (This has to be stdlib only, by the way, I
> can't introduce any new modules into the application so pyparsing is
> not an option.)
> 
> The challenge is to turn a string like this:
> 
>     a=1,b="0234,)#($)@", k="7"
> 
> into this:
> 
>     [("a", "1"), ("b", "0234,)#($)#"), ("k", "7")]

But the starting string IS is csv format, where the values are strings 
with the format name=string.

 >>> import csv
 >>> myDialect = csv.excel
 >>> myDialect.skipinitialspace = True # needed for space before 'k'
 >>> a=list(csv.reader(['''a=1,b="0234,)#($)@", k="7"'''], myDialect))[0]
 >>> a
['a=1', 'b="0234', ')#($)@"', 'k="7"']
 >>> b=[tuple(s.split('=',1)) for s in a]
 >>> b
[('a', '1'), ('b', '"0234'), (')#($)@"',), ('k', '"7"')]

Terry Jan Reedy