Not understanding dictionaries

[bowlofred]

items() returns all of the keys/values in the dictionary, one tuple at a time. So each time through the loop, k is set to one of the keys, and v to the corresponding value of that key.

>>> d = {'key': 'value', 'A': 1, 'B': 2}
>>> list(d.items())
[('key', 'value'), ('A', 1), ('B', 2)]

The empty string is probably a typo. I'd guess someone wanted a blank space between the key and the value in the print and it became empty instead of a space.

This is the form of an augmented assignment. It's basically the same thing as writing Item_total = Item_total + v