On Oct 19, 12:24 am, stef mientki <[EMAIL PROTECTED]> wrote: > I generate dynamically a sequence of values, > but this "sequence" could also have length 1 or even length 0. > > So I get some line in the form of: > line = '(2,3,4)' > line = '' > line = '(2)' > (in fact these are not constant numbers, but all kind of integer > variables, coming from all over the program, selected from a tree, that > shows all "reachable" variables) > > So in fact I get the value from an exec statement, like this > exec 'signals = ' + line > > Now I want to iterate over "signals", which works perfect if there are 2 > or more signals, > but it fails when I have none or just 1 signal. > for value in signals : > do something > > As this meant for real-time signals, I want it fast, so (I think) I > can't afford extensive testing. > > Any smart solution there ?
First: don't collect data into strings - python has many container types which you can use. Next, your strings look like they're supposed to contain tuples. In fact, tuples are a bit awkward sometimes because you have to use '(a,') for a tuple with one element - (2) isn't a tuple of length one, it's the same as 2. Either cope with this special case, or use lists. Either way, you'll have to use () or [] for an empty sequence. -- Paul Hankin -- http://mail.python.org/mailman/listinfo/python-list
