Check for dict key existence, and modify it in one step.

[rodrigo]

evan,

yes, it does help. Works like it should:

class CountingDictionary(dict):
    def increment(self, key, delta=1):
        self[key] = self.get(key, 0) + delta

d = CountingDictionary()
d.increment('cat')
d.increment('dog',72)
print d

>>> {'dog': 72, 'cat': 1}

Thanks!