求下列多项式前k项的和,1 - 1/2 + 2/3 - 3/4 +4/5 - 5/6 + ... 要求结果表示为真分式形式

def calculate_fractional_sum(n):
    numerator = 1
    denominator = 2
    sum_result = 0
    for i in range(1, n):
        sum_result += numerator / denominator
        numerator += 1
        denominator += 1
    result = 1 - sum_result
    return result
result = calculate_fractional_sum(6)
print(f"The result in fractional form is: {result}")