Python dictionary increment

Question

In Python it\'s annoying to have to check whether a key is in the dictionary first before incrementing it:

if key in my_dict:
  my_dict[key] += num
else:
  m         


        

Answer 1

transform:

if key in my_dict:
  my_dict[key] += num
else:
  my_dict[key] = num

into the following using setdefault:

my_dict[key] = my_dict.setdefault(key, 0) + num