#input: [[18, 20],[45, 2],[61, 12],[37, 6],[21, 21],[78, 9]]

def openOrSenior(data):
    return ["Senior" if age >= 55 and handicap > 7 else "Open" for age, handicap in data]

Alternatywne rozwiązanie:
def openOrSenior(data):
    return ["Senior" if person[0] >= 55 and person[1] > 7 else "Open" for person in data]