Preventing code duplication in Django

Question

I have these 2 functions that are almost the same:

def handle_keywords(self, scan_id):
 keywords = Keyword.objects.all()
 for kwrd in keywords:
 self.process_rss_url(kwrd.rss, SourceType.GOOGLE_ALERTS, kwrd.id, kwrd.last_scan_time, scan_id)
 kwrd.last_scan_time = timezone.now()
 kwrd.save()
def handle_rss(self, scan_id):
 all_rss = RSS.objects.all()
 for rss in all_rss:
 self.process_rss_url(rss.feed_url, SourceType.RSS, rss.id, rss.last_scan_time, scan_id)
 rss.last_scan_time = timezone.now()
 rss.save()

What is a good way to reduce the code duplication?

Answer 1

Try this:

def generate_func(url_attr, type_class, source_type):
 def f(self, scan_id):
 for keyword in type_class.objects.all():
 self.process_rss_url(getattr(keyword, url_attr), source_type, keyword.id, keyword.last_scan_time, scan_id)
 keyword.last_scan_time = timezone.now()
 keyword.save()
 return f
handle_keywords = generate_func('rss', Keyword, SourceType.GOOGLE_ALERTS)
handle_rss = generate_func('feed_url', RSS, SourceType.RSS)

• Snowbody: The "keywords" temp is unnecessary. I think SourceType.RSS and SourceType.GOOGLE_ALERTS are constants, but it's not certain from the code given.
• Solomon Ucko: @Snowbody Thanks for pointing out about keywords. Why does it matter if those are constants?
• Snowbody: Because then they can be passed in and used directly, saving a call to getattr()
• Solomon Ucko: @Snowbody That's what I was wondering. I'll change that.