如何为Python勾股三元组输出添加英文序数词序号？

问题背景 #

现有一段生成指定范围内勾股三元组的Python代码，输出仅打印三元组列表，需要修改代码，让每个输出的三元组前自动添加对应的英文序数词（如First、Second），并保持指定的格式对齐。

原代码 #

def Pythagorean_Triplets(N) :
    c = 4 
    m = 2
    while c < N :
        for n in range(1, m) :
            a = m * m - n * n
            b = 2 * m * n
            c = m * m + n * n
            if c > N :
                break    
            print([a, b, c])    
        m = m + 1
N = int(input("\nEnter the value of N uptil which you want to get the Pythagorean Triplets: "))
print(f"\nPythagorean Triplets uptil {N} are: ")
Pythagorean_Triplets(N)

原输出示例 #

Enter the value of N uptil which you want to get the Pythagorean Triplets: 20

Pythagorean Triplets uptil 20 are: 
[3, 4, 5]
[8, 6, 10]
[5, 12, 13]
[15, 8, 17]
[12, 16, 20]

期望输出格式 #

Enter the value of N uptil which you want to get the Pythagorean Triplets: 20

Pythagorean Triplets uptil 20 are: 
First list  :  [3, 4, 5]
Second list :  [8, 6, 10]
Third list  :  [5, 12, 13]
Fourth list :  [15, 8, 17]
Fifth list  :  [12, 16, 20]

修改后的代码 #

def get_ordinal(n):
    # 基础序数词映射，覆盖常用场景，如需更多可扩展
    ordinals = {
        1: "First", 2: "Second", 3: "Third", 4: "Fourth", 5: "Fifth",
        6: "Sixth", 7: "Seventh", 8: "Eighth", 9: "Ninth", 10: "Tenth",
        11: "Eleventh", 12: "Twelfth", 13: "Thirteenth", 14: "Fourteenth",
        15: "Fifteenth", 16: "Sixteenth", 17: "Seventeenth", 18: "Eighteenth",
        19: "Nineteenth", 20: "Twentieth"
    }
    if n in ordinals:
        return ordinals[n]
    # 处理大于20的情况，按规则生成序数词
    suffix = "th"
    if n % 10 == 1 and n % 100 != 11:
        suffix = "st"
    elif n % 10 == 2 and n % 100 != 12:
        suffix = "nd"
    elif n % 10 == 3 and n % 100 != 13:
        suffix = "rd"
    return f"{n}{suffix}".capitalize()

def Pythagorean_Triplets(N) :
    c = 4 
    m = 2
    count = 1  # 计数器，记录三元组序号
    while c < N :
        for n in range(1, m) :
            a = m * m - n * n
            b = 2 * m * n
            c = m * m + n * n
            if c > N :
                break    
            # 获取序数词并格式化输出
            ordinal = get_ordinal(count)
            print(f"{ordinal} list :  {[a, b, c]}")
            count += 1
        m = m + 1

N = int(input("\nEnter the value of N uptil which you want to get the Pythagorean Triplets: "))
print(f"\nPythagorean Triplets uptil {N} are: ")
Pythagorean_Triplets(N)

修改说明 #

1. 新增序数词生成函数get_ordinal：
   • 内置1-20的标准序数词映射，保证输出格式符合要求；
   • 对大于20的数字，通过规则自动生成对应的序数词（如21st、22nd等），适配更多场景。
2. 添加序号计数器count：
   • 在函数内部初始化计数器，每生成一个有效三元组就递增；
   • 打印时调用get_ordinal获取对应序数词，配合格式化字符串实现对齐输出。

内容的提问来源于stack exchange，提问作者Jerin Joy