Exercise for reference: 

Filter the dictionary by removing all items with a value of greater than 1.

d = {"a": 1, "b": 2, "c": 3}

Answer: 

d = {"a": 1, "b": 2, "c": 3}
d = dict((key, value) for key, value in d.items() if value <= 1)
print(d)

Explanation: 

Here we're using a dictionary comprehension. The comprehension is the expression inside dict() . The comprehension iterates through the existing dictionary items, and if an item is less or equal to 1, the item is added to a new dict. This new dict is assigned to the existing variable d  , so we end up with a filtered dictionary in d.