os.path.isdir question

[lampshade]

Hello,

I'm having some problems with  os.path.isdir  I think it is something
simple that I'm overlooking.

#!/usr/bin/python
import os

my_path = os.path.expanduser("~/pictures/")
print my_path
results = os.listdir(my_path)
for a_result in results:
    if os.path.isdir(str(my_path) + str(a_result)):
        results.remove(a_result)

for x in results: print x

The problem is, that the directories are never removed.  Can anyone
point out what I'm missing that is causing the bug?  Is there a better
way of doing this?

Thanks,