Memoized fibonacci sequence in python

fib.py

"""
Each new term in the Fibonacci sequence is generated by adding the previous two
terms. By starting with 1 and 2, the first 10 terms will be:

    1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...

    By considering the terms in the Fibonacci sequence whose values do not
    exceed four million, find the sum of the even-valued term
"""

memory = {
    0: 0,
    1: 1,
}
def fib(n):
    if n not in memory:
        memory[n] = fib(n - 1) + fib(n - 2)
    return memory[n]

# fib(38) > 4*10^6
# we start at 2 so we get the same pattern...
print(
    sum(
        [
            y for y in
            [fib(x) for x in range(2, 38)]
            if not y % 2 and y < 4000000
        ]
    )
)