Python - 递增的数字链不能正常工作

Question

我有一个程序将三个数字作为命令行参数。然后它应该显示一个数字列表，这些数字与前两个数字相差相同，列表的长度是第三个数字。

当前两个输入之间的差异为负或零时，我当前的代码不起作用。

这里是三个测试用例:

1. 这有效(但总和是错误的):

   python suite.py 1 2 10  
   > 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 56
   

   总和应为 55。

2. 这失败了:

   python suite.py 30 27 8
   > 0
   

   输出应该是

   > 30 27 24 21 18 15 12 9 = 156
   

3. 这失败了:

   python suite.py 6 6 6
   > 6
   

   输出应该是

   > 6 + 6 + 6 + 6 + 6 + 6 = 36
   

代码如下:

import sys

def suite(premier, second, nombre):
    message = ""
    message2 = ""
    if second < premier:
        diff = (premier - second) * -1
    else:
        diff = second - premier
    maximum = premier + (diff * nombre)
    i = premier
    total = premier
    for i in range(premier, maximum, diff):
        message += str(i) + " + "
        message2 = message[:-3]
        total += i
    message2 += " = " + str(i)
    return message2

def main():
    premier = int(sys.argv[1])
    second = int(sys.argv[2])
    nombre = int(sys.argv[3])
    if premier == second:
        resultat = premier
    else:
        resultat = suite(premier, second, nombre)
    print(resultat)

if __name__ == "__main__":
    main()

Answer 1

这是一个更 Pythonic 的替代方案:

import sys 

def suite(premier, second, nombre):
    diff = second - premier
    if diff == 0:
        nombres = [premier] * nombre
    else:
        maximum = premier + diff * nombre
        nombres = range(premier, maximum, diff)
    gauche = ' + '.join(map(str, nombres))
    droite = sum(nombres)
    return '%s = %d' % (gauche, droite)

def main():
    premier = int(sys.argv[1])
    second = int(sys.argv[2])
    nombre = int(sys.argv[3])
    print(suite(premier, second, nombre))

if __name__ == "__main__":
    main()

对于 1 2 10，它输出:

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55

对于 30 27 8:

30 + 27 + 24 + 21 + 18 + 15 + 12 + 9 = 156

对于 6 6 6:

6 + 6 + 6 + 6 + 6 + 6 = 36