1.
def dict_value_count(d, value):
    count = 0

    for k in d:
        if d[k] == value:
            count += 1

    return count


2.
letter_count = {"d":1, "a":1, "v":1, "e":1}

We can declare a dictionary in the same way that it's
printed out, i.e. a comma separated list of key:value
pairs inside curly braces.