On or about 2009 Sep 8, at 1:51 PM, Alan Gauld indited:
"kevin parks" <k...@me.com> wrote
What would this look like if i want to use a straight up built-in
dictionary type and not the collections.defaultdict.
Not too different:
import collections
def foo():
lookup = collections.defaultdict(list)
# Doug: lookup = dict()
x = range(10)
y = range(5, 15)
z = range(8, 22)
sets = {'x': set(x), 'y': set(y), 'z': set(z)}
for key, value in sets.items():
for element in value:
lookup[element] = lookup.get(element, []).append(key)
# Doug: That doesn't do what you think it does, it won't insert the
new list into the dictionary.
# Doug: I think what you want is lookup.setdefault(element,
[]).append(key)
print "\n", lookup, "\n\n"
for x in lookup:
lookup[x].sort()
print x, lookup[x]
print "\n"
At least I think thats all you need here.
>>> help(dict.setdefault)
setdefault(...)
D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D
-Doug
-Doug
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