Gregory Piñero wrote:
> def add_freqs(freq1,freq2):
> """Add two word freq dicts"""
> newfreq={}
> for key,value in freq1.items():
> newfreq[key]=value+freq2.get(key,0)
> for key,value in freq2.items():
> newfreq[key]=value+freq1.get(key,0)
> return newfreq
> Any ideas on doing this task a lot faster would be appriciated.
With items() you copy the whole dictionary into a list of tuples;
iteritems() just walks over the existing dictionary and creates one tuple
at a time.
With "80% overlap", you are looking up and setting four out of five values
twice in your for-loops.
Dump the symmetry and try one of these:
def add_freqs2(freq1, freq2):
total = dict(freq1)
for key, value in freq2.iteritems():
if key in freq1:
total[key] += value
else:
total[key] = value
return total
def add_freqs3(freq1, freq2):
total = dict(freq1)
for key, value in freq2.iteritems():
try:
total[key] += value
except KeyError:
total[key] = value
return total
My guess is that add_freqs3() will perform best.
Peter
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