Python: practical uses for summing up dictionary keys?

Question

Today I've learned that print(sum({key1:value1, key2:value2, keyn:valuen, })) outputs the sum of all the keys.

For example:
print(sum({1:2,3:4,5:6, 100:200})) outputs 109

What kind of practical use could this have?

Answer 1

Mirielle[ InAcTiVe ] , he has asked about to sum the keys and not the values. But i go with you, that in most cases the values are processed and not the keys. May be its just an exercise?

Answer 2

From Mirielle[ InAcTiVe ] example,

May be here, to know the number of working days, keys works as will be equal to number of keys..

And if you take it as
"num_of_sales in a day" : "amount" then sum of keys is sum of sales..
Sum of values is sum of amount..

Answer 3

when you loop through a dictionary without passing a dictionary function (ie. dict.items()), it returns the keys. That is probably why it’s adding up the keys