Kent Johnson wrote:
Vaibhav.bhawsar wrote:
i have this code to print every new element in a list only when the
list length changes (while the list is updated by a thread running
elsewhere)...I was wondering if there is a pythonic way to do this?
how does one know when there is a new element in the list?
prevlength = 0
while geoCode.running:
places = geoCode.getResults() #returns a list with most up to
date elements..the list grows as the thread that updates it
if len(places) > prevlength:
print places[prevlength]
prevlength = len(places)
Ouch. This loop will chew up CPU time unless there is some kind of
delay in getResults(). If the intent of the loop is to print every new
value placed in the list, there is no guarantee that it will work.
If you are using the list to communicate results between two threads
you should see if queue.Queue meets your needs. It is thread safe and
has blocking access so you don't have to use a busy loop.
Evey time someone recommends Queue I think "oh boy this will really help
me". Then I go to the Library Reference, read the Queue docs and think
"oh boy who can help me understand this". Even the sample code is
confusing.
Is there some other documentation or example?
--
Bob Gailer
919-636-4239 Chapel Hill, NC
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