How to sum all the keys of a dictionary value to the same dictionary value
<p>Let's say I have a dictionary that has
{'a' : '0',
 'b' : '2',
 'a' : '3',
 'b' : '5',}</p>

<p>I want the dictionary to say {'a' : '3'
                              'b' : '7'}</p>

<p>How would I do this ? </p>

<p>You can't create dictionary which contains the same key twice. The definition of the dictionary is that you can store in it every key-value option only once.</p>

python dictionary key