python进行二次方程式计算的实例讲解

import math
import unicodedata
def is_number(s):
  try:
    float(s)
    return True
  except ValueError:
    pass
  try:
    unicodedata.digit(s)
    return True
  except (TypeError, ValueError):
    pass
  return False

# -*- coding:utf-8 -*-
#! python2
import math
class Result:
 result1 = 0
 result2 = 0
 def __init__(self, r1, r2):
  self.result1 = r1
  self.result2 = r2
 def __return__(self):
  return Result(self.result1, self.result2)
def main(a, b, c):
 num = b*b-4*a*c
 if num < 0:
  return 'no result'
 elif num == 0:
  return Result((-b+math.sqrt(num))/(2*a), (-b+math.sqrt(num))/(2*a))
 else:
  return Result((-b+math.sqrt(num))/(2*a), (-b-math.sqrt(num))/(2*a))
if __name__ == '__main__':
 result = main(1, 2, 1)
 print result.result1, result.result2