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下面这样好像检测不到变量类型错误
>>> quadratic('c',3,'-c')
Traceback (most recent call last):
File "<pyshell#5>", line 1, in <module>
quadratic('c',3,'-c')
sq=math.sqrt(b**2-4*a*c)
TypeError: can't multiply sequence by non-int of type 'str'
先检测变量类型，再计算sq=math.sqrt(b**2-4*a*c)
# _*_ coding: utf-8 _*_
import math
def quadratic(a, b, c):
if not isinstance(a,(float,int)):
raise TypeError('bad operand type')
if not isinstance(b,(float,int)):
raise TypeError('bad operand type')
if not isinstance(c,(float,int)):
raise TypeError('bad operand type')
sq=math.sqrt(b**2-4*a*c)
if sq <0:
print('this has no solution')
else:
x1=float(-b+sq)/(2*a)
x2=float(-b-sq)/(2*a)
return (x1,x2)
quadratic('c',3,'-c')
Traceback (most recent call last):
File "<pyshell#6>", line 1, in <module>
quadratic('c',3,'-c')
File "C:/Users/mtk11999/Desktop/My Job/python_test\quadratic_test.py", line 8, in quadratic
if not isinstance(a,(float,int)):
嗯，确实应该分开检测，不过你的if语句可以合并成
if not (isinstance(a,(int, float)) and isinstance(b, (int, float)) and isinstance(c,(int,float))): raise TypeError('请输入数字.')
- 1
星辰德法
sq = b*b - 4*a*c
if not isinstance(a+b+c,(int,float)):
raise TypeError("参数输入错误")
elif sq < 0:
print("方程无解")
else:
x_1 = (-b + math.sqrt(sq))/(2*a)
x_2 = (-b - math.sqrt(sq))/(2*a)
return x_1, x_2