Python: Finding a (string) key in a dictionary that contains a substring

Question

In my script I build a dictionary of keys(albums) mapped to artists(values) so that I can do a quick lookup of what artists made what albums. However, I want the user to be able to find all albums which contain a substring. For example a search on "Light" should return

[Light Chasers] = Cloud Cult and also [Night Light] = Au Revoir Simone

What's the best way to do this? Should I even be using a dictionary?

score 21 · Accepted Answer · answered Jul 15 '10 at 05:06

21

[(k, v) for (k, v) in D.iteritems() if 'Light' in k]

answered Jul 15 '10 at 05:06

Ignacio Vazquez-Abrams

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Ah, I was thinking of something like this, I just wouldn't have expressed it so elegantly. I secretly was hoping there might be some sneaky more efficient solution though :) – Sushisource Jul 15 '10 at 05:08
If performance is critical, memory is cheap, and the record collection changes only rarely, you could build another "index" dict with individual words as keys and list-of-albums-containing-that-word as values. Unless you're doing a lot of lookups and have a truly huge record collection it's probably not worthwhile. – Russell Borogove Jul 15 '10 at 07:26

score 0 · Answer 2 · answered May 06 '13 at 19:32

0

If you ever just need the first album containing the text, here's a fast way:

try:
    return ('[%s] = %s' % (k, D.get(k)) for k in D if search_string.lower().strip() in k.lower()).next()
except StopIteration:
    return 'No matches found'

answered May 06 '13 at 19:32

hobs

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Python: Finding a (string) key in a dictionary that contains a substring

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