Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.python > #70607

Proper deletion of selected items during map iteration in for loop

Date 2014-04-25 10:53 -0700
From Charles Hixson <charleshixsn@earthlink.net>
Subject Proper deletion of selected items during map iteration in for loop
Newsgroups comp.lang.python
Message-ID <mailman.9503.1398448502.18130.python-list@python.org> (permalink)

Show all headers | View raw


What is the proper way to delete selected items during iteration of a 
map?  What I want to do is:

for (k, v) in m.items():
    if f(k):
       #  do some processing of v and save result elsewhere
       del m[k]

But this gives (as should be expected):
         RuntimeError: dictionary changed size during iteration
In the past I've accumulated the keys to be deleted in a separate list, 
but this time there are likely to be a large number of them, so is there 
some better way?

-- 
Charles Hixson

Back to comp.lang.python | Previous | Next | Find similar | Unroll thread


Thread

Proper deletion of selected items during map iteration in for loop Charles Hixson <charleshixsn@earthlink.net> - 2014-04-25 10:53 -0700

csiph-web