Is there any Iterator type example?

[Thomas Moore]

Hi:

Is there any example about how to use Iterator type?

--Thomas

[DonQuixoteVonLaMancha]

How about this one:

import os
from os.path import join

def py_files(dir):
for root, dirs, files in os.walk(dir):
for name in files:
if name.lower().endswith(".py"):
yield join(root,name )

if __name__=="__main__":
dir= "C:\\Python23\\"
for f in py_files(dir):
print f

In my opinion, iterators have two advantages:
1. They can make it easier to iterate over complicated structures, like
a file tree in the above example.
2. Since they store only information on how to access the next item,
they need often less memory. For example, map(f, list) creates a
new
list [f(L) for L in list], while itertools.imap(f,list) creates an
iterator object.
The iterator object often needs much less memory than the new list.

There was also a dicussion on this topic on the tutor list two days
ago, maybe you'd like to join.

Kind regards,
Karsten.

Thomas Moore schrieb:

Hi:

Is there any example about how to use Iterator type?

--Thomas