[EMAIL PROTECTED] wrote: > On Aug 23, 11:27 am, Ladislav Andel <[EMAIL PROTECTED]> wrote: > >> Hi, >> what would be the most efficient way to do following? >> >> I have a list of dictionaries taken from DB e.g. >> dblist = [{'id:1, 'host':'google.com','ip_address':'1.2.3.4'}, >> {'id:3, 'host':'yahoo.com','ip_address':'5.6.7.8'}, >> {'id:9, 'host':'msn.com','ip_address':'11.3.2.3'}] >> >> and list of object instances in memory(it's just for example) >> which are looping within itself and testing particular hosts >> >> memlist = [<instance 1>,<instance 2>] >> memlist[0].id is 1 and memlist[0].host is google.com etc. >> memlist[1].id is 9 and memlist[1].host is msn.com etc. >> >> Now I want to add a new instance to memlist since id=3(in dblist) is not >> in memlist. >> How would you iterate through it and insert a new instance? >> >> The result should be: >> memlist = [<instance 1>,<instance 2>, <instance 3>] >> memlist[0].id is 1 and memlist[0].host is google.com etc. >> memlist[1].id is 3 and memlist[1].host is yahoo.com etc. >> memlist[2].id is 9 and memlist[2].host is msn.com etc. >> >> Furthermore, I can have the opposite situation. >> This time I need to remove from memlist a host which is not in dblist. >> How would you do this? >> >> The way how it works is that DBlist is loaded every 10 minutes and >> compares with memlist. >> The memlist should be the same as dblist. >> >> Could you help me, please? >> I'm working on my version of this but somebody might be quicker than me. >> In case I have it done I will post it. >> >> Thanks, >> Lada >> >> There is >> >> and wt >> > > On lists that change in memory, I use the following looping structure: > > for i in range(len(in_memory_list)-1,-1,-1) > > well, actually I will need to iterate over 2 sequences which are not the same length and synchronize it against the dblist i have. But I will look at your post. Thanks a lot.
Lada > This loops over the list backwards. I found this method here: > http://mail.python.org/pipermail/python-list/1999-September/012451.html > > Hopefully this will fulfill your needs. I've used it to great effect! > > Mike > > -- http://mail.python.org/mailman/listinfo/python-list