dictFind.py

def dictFind():

    seen = dict()

    with open(file, 'r') as infile:
        for line in infile:
            num = int(line)
            complement = 2020-num
            if complement in seen:
                success(num, complement)
                return
            seen[num] = True

    print ("Finished loop, no pairs found that sum to 2020")