conditions on undefined keys in defaultdict

Question

I am new to python I wanna write a code using defaultdict in collections module in which , something like this: defaultdict (lambda:'0') but I want the values of only those undefined keys to 0 for which key is greater than 0 like for eg: I have this dict = {'24' : 3 ,'43' : 6} for dict['80'] it should be 0 but for dict['-5'] it should be 1. Can someone please help

Answer 1

Don't use defaultdict. Instead, subclass UserDict

from collections import UserDict

class MyDict(UserDict):
    def __missing__(self, key):
        return 0 if int(key) > 0 else 1

d = MyDict({'24' : 3 ,'43' : 6})
print(d['24'])
print(d['80'])
print(d['-5'])

Outputs

3
0
1