Newbie: list comprehension troubles..

mm mattaman at
Mon Aug 24 01:27:21 CEST 2009

Hi, I'm trying to replace this...

        # this works but there must be a more pythonic way, right?
        tlist = []
        for obj in self.objs:
            t = obj.intersect(ray)
            if (t != None):

with a list comprehension- can it be done?

What I need to do is iterate over a list of graphics primitives and
call their intersect method. If the returned t value is not None then
I want to store the obj refernence and its t value in a list of tuples
for further processing. I've tried stuff like ...

        tlist = [(obj,t) for obj,t in (self.objs, obj.intersect(ray))
if (t != None)]
        tlist = [(obj,t) for obj in self.objs for t in obj.intersect
(ray) ]
        print ">>> ",len(tlist), tlist

but they don't work. Any help greatly appreciated. matt

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