Finding some of two with/without doubles

input.txt

67
5 100 200 30 56 456 4 37 44 38 5 9999 2 44 89 100 5435 324

two_sum.py

from sys import getsizeof


def two_sum(string):
    seen = set()
    target, nums = string.split('\n')
    target = int(target)
    check_doubles = False if target % 2 != 0 else True

    for num in (int(n) for n in nums.split()):

        if target > num and num not in seen:
            seen.add(num)

        if num in seen and check_doubles:
            if target == num * 2:
                print(f"{num, num} = {target}")
                return 1

        if len(seen) >= 2:
            if target - num in seen:
                print(f"{target - num, num} = {target}")
                return 1

    return 0


if __name__ == '__main__':

    INPUT: str = """67
    5 100 200 30 56 456 4 37 44 38 5 9999 2 44 89 100 5435 324"""

    t, num_str = INPUT.split('\n')
    nums_gen = (int(n) for n in num_str.split())
    nums_list = list(nums_gen)

    print(f"Size of num string: {getsizeof(num_str)}")
    print(f"Size of generator with nums: {getsizeof(nums_gen)}")
    print(f"Size of list with nums: {getsizeof(nums_list)}")
    print(f"Size of tuple  with nums: {getsizeof(tuple(nums_list))}")

    with open('input.txt', 'r') as input_file:
        result = two_sum(input_file.read())

    if result:
        print('Yay!')

    with open('output.txt', 'w') as output_file:
        output_file.write(str(result))

two_sum_v2.py

class TwoSum:
    CHUNK_SIZE = 1024
    target = 0
    seen = set()

    def read_and_write(self, input_f, output_f):
        with open(input_f, 'r') as input_file:
            self.target = int(input_file.readline())
            result = 0
            while True:
                chunk = input_file.read(self.CHUNK_SIZE)
                if chunk:
                    result = self.compute(chunk)
                    if result:
                        break
                else:
                    print('EOF')    # Result will be 0
                    break

        with open(output_f, 'w') as output_file:
            output_file.write(str(result))

    def compute(self, nums):
        check_doubles = False if self.target % 2 != 0 else True
        for num in (int(n) for n in nums.split()):
            if self.target > num and num not in self.seen:
                self.seen.add(num)
            if num in self.seen and check_doubles:
                if self.target == num * 2:
                    print(f"{num, num} = {self.target}")
                    return 1
            if len(self.seen) >= 2:
                if self.target - num in self.seen:
                    print(f"{self.target - num, num} = {self.target}")
                    return 1

        return 0


if __name__ == '__main__':
    INPUT = 'input.txt'
    OUTPUT = 'output.txt'
    c = TwoSum()
    c.read_and_write(INPUT,OUTPUT)