Python - Incremential chain of numbers not working fine -

i have program takes 3 numbers command line arguments. should display list of numbers differ same amount first two, length of list being third number.

my current code not work when difference between first 2 inputs negative or zero.

here 3 test cases:

1. this works (but sum wrong):

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

   sum should 55.

2. this fails:

   python suite.py 30 27 8 > 0 

   the output should

   > 30 27 24 21 18 15 12 9 = 156 

3. this fails:

   python suite.py 6 6 6 > 6 

   the output should be

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

here's code:

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

here's more pythonic alternative :

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() 

for 1 2 10, outputs:

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

for 30 27 8:

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

for 6 6 6:

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