I posted this answer on SO and thought I should share it here for the benefit of other and future readers:
---------------------------------------------------------------------- The accepted answer is spot on about the regex, but since we're discussing optimization, I thought I should note that the code for checking whether a project exists could be modified to generate a much quicker query, especially in other contexts where you could be counting millions of rows needlessly. Call this 'best practices' advice, if you will. p = Project.objects.filter(projectName__exact = aProjectName).count()if p > 0: could instead be if Project.objects.filter(project_name__iexact=aProjectName).exists(): for two reasons. First, you're not using p for anything so there's no need to store it as a variable as it increases readability and p is an obscure variable name and the best code is no code at all<http://www.codinghorror.com/blog/2007/05/the-best-code-is-no-code-at-all.html> . Secondly, by This way we only ask for a single row instead of saving the results to the queryset cache. Please see the official Queryset API docs<https://docs.djangoproject.com/en/dev/ref/models/querysets/#exists> , a related question on Stack Overflow<http://stackoverflow.com/questions/14368205/django-any-difference-between-queryset-nonzero-and-queryset-exists/14369747#14369747> and the discussion about the latter on the django-developers group<https://groups.google.com/forum/#!msg/django-developers/L4irIYGPUWM/wK7fQ1q_SsYJ> . Additionally, it is customary in python (and Django, naturally) to name your fields lower_cased_separated_by_underscores. Please see more about this on the Python Style Guide (PEP 8)<http://www.python.org/dev/peps/pep-0008/> . ---------------------------------------------------------------------- Cheers, AT On Wed, Jan 30, 2013 at 4:07 PM, Shawn H <[email protected]> wrote: > Indeed it was. As Alisdair posted, simplify the regex and validate > elsewhere. Thanks. > > On Wednesday, January 30, 2013 11:26:51 AM UTC-6, fgallina wrote: >> >> 2013/1/30 Shawn H <[email protected]>: >> > I posted this question yesterdat at stack overflow, but I'm wondering >> if >> > this is a bug. I have a url that accepts one text parameter, allows >> spaces, >> > and calls a very simple view that checks if there are objects with a >> project >> > name that matches the text parameter value. The view returns a simple >> json >> > string indicating whether there's a project with that name already in >> the >> > database. It works great, repeatedly, with short parameter values. It >> > locks up python on certain long string values. I've tested up to 50 >> > characters, and just length doesn't trigger it. What does seem to >> > repeatedly trigger it are long strings with multiple spaces. I've >> tested my >> > url regex matching and those long strings match just fine; my concern >> is >> > that for some reason inside the view that long string is causing >> problems. >> > I'm using Django 1.4 with the built in webserver for testing. Any help >> that >> > can be provided will be greatly appreciated. >> > >> >> I have a strong feeling it is related on how your regexp matches the >> passed string, I don't know why in the world you would sanitize the >> project's name directly in the url and not the view, in any case if >> the user happen to enter garbage then filter will not find anything, >> right? Also this seems a job for a GET parameter rather than a view >> param, but YMMV. >> >> >> Regards, >> -- >> Fabián E. Gallina >> http://www.from-the-cloud.com >> > -- > You received this message because you are subscribed to the Google Groups > "Django users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/django-users?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/django-users?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
