switch recipe?

[Chris Liechti]

"Mark McEahern" <mark at mceahern.com> wrote in
news:mailman.1026501403.17010.python-list at python.org: 

>   from __future__ import generators
> 
>   def make_switch(*args):
>       """Return a generator that loops through args."""
>       if not args:
>           raise RuntimeError("Missing parameter: args.")

this should be a TypeError, as the builtins raise that too

  raise TypeError("switch() takes at least one argument")

>       def switch():
>           i = n = 0
>           while True:
>               i = n % len(args)
>               yield args[i]
>               n += 1
>       return switch
> 
> Is switch a bad name for this?

definetly yes ;-) as a C programmer, i expect something completly 
different... (switch() {case x:})

> Can anyone suggest a better name? 

how about "repeat"? 'cause that's what it does.

> Other improvements?  

isn't this simpler, more obvious what it does, and still doing what you 
want:

>>> from __future__ import generators
>>> def repeat(*args):
... 	if not args: args = [None]    	#optionaly to catch empty args
... 	while 1:
... 		for x in args: yield x
... 		
>>> zip(range(10), repeat('even', 'odd'))
[(0, 'even'), (1, 'odd'), (2, 'even'), (3, 'odd'), (4, 'even'), (5, 'odd'), 
(6, 'even'), (7, 'odd'), (8, 'even'), (9, 'odd')]
>>>


chris

-- 
Chris <cliechti at gmx.net>