On Thu, Oct 23, 2008 at 2:03 PM, Jani Tiainen <[EMAIL PROTECTED]> wrote:
> I have rather simple 'Address' object that contains streetname, > number, my own status and x,y coordinates for it. I have two lists > both containing approximately 30000 addresses. > > I've defined __eq__ method in my class like this: > > def __eq__(self, other): > return self.xcoord == other.xcoord and \ > self.ycoord == other.ycoord and \ > self.streetname == other.streetname and \ > self.streetno == other.streetno > > But it turns out to be very, very slow. > > Then I setup two lists: > > list_external = getexternal() > list_internal = getinternal() > > Now I need get all all addresses from 'list_external' that are not in > 'list_internal', and mark them as "new". > > I did it like this: > > for addr in list_external: > if addr not in list_internal: > addr.status = 1 # New address > > But in my case running that loop takes about 10 minutes. What I am > doing wrong? > Sorry I don't see what you're doing wrong, except I'lde write "if not ( addr in list internal) :" but you might consider using dictionaries. A couple of days ago I did some speed comparison between C and Python. We used the lookup of a string in a hash table (= dictionary in Python), the results were amazing: Search string was between 50 and 100 characters. The table / dictionary was build with 10 million strings, each also 50 .. 100 characters long. We repeated the search 100 million times and measured the time. Code length: C, about 150 lines of unreadable code Python: about 20 lines of very easy to read code lines Development time C : 1.5 days Python : 20 minutes Execution time: C: 20 seconds Python: 11 seconds !! Who dares to ask Python is slow ? cheers, Stef C: 20 seconds Python > -- > > Jani Tiainen > -- > http://mail.python.org/mailman/listinfo/python-list >
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