程序基本机构

 1 import math
 2 def main():
 3     print("求二次方程的实根\n")#换行，反斜杠和n
 4     a,b,c=eval(input("输入二次函数的系数(a,b,c）:"))#用逗号隔开，同时输入三个数
 5     delt=b**2-4*a*c
 6     if delt>0:
 7         delt=math.sqrt(b**2-4*a*c)
 8         root1=(-b+delt)/(2*a)
 9         root2=(-b-delt)/(2*a)
10         print("二次函数的实根为:",root1,root2)
11 #      print("二次函数的实根为root1=%f,root2=%f:"%root1,%root2) 编译不通，留看
12     elif delt==0:
13         delt=math.sqrt(delt)
14         root1=(-b+delt)/(2*a)
15         print("相同的实根",root1)
16     else:
17         print('没有实根')
18   
19 main()

if-elif-elif-else 多个互斥的判断语句

 1 from math import *
 2 def main():
 3     print("二次方程求根方法")
 4     a,b,c=eval(input("输入系数："))
 5     delta=b**2-4*a*c
 6     if delta<0:
 7         print("方程没有实根")
 8     else:
 9          if delta==0:
10              root=-b/2*a
11              print("相同的实根",root)
12          else delta>0:
13              delta=sqrt(delta)
14              root1=(-b+delta)/(2*a)
15              root2=(-b-delta)/(2*a)
16              print("实根为：",root1,root2)
17 
18 main()

 1 def main():
 2     try:
 3         number1,number2=eval(input("enter two number,separated by a comma\n"))
 4         result=number1/number2
 5 
 6     except ZeroDivisionError:
 7         print("Division by zero!")
 8     except SyntaxError:
 9         print("A comma may be missing in the input")
10     except :
11         print("Something wrong in the input")
12     else:
13         print("No excepting,the result is",result)
14     finally:
15         print("executing the final clause")
16 main()

 1 import math
 2 def main():
 3     print('this program finds the real solutions to a quadratic')
 4     try:
 5         a,b,c=eval(input("please enter the coefficients(a,b,c)\n"))
 6         discroot=math.sqrt(b*b-4*a*c)
 7         root1=(-b+discroot)/(2*a)
 8         root2=(-b-discroot)/(2*a)
 9         print("the solutions are:",root1,root2)
10     except:
11         print("some thing went trong")
12     
13 main()

 1 import math
 2 def main():
 3     print('this program finds the real solutions to a quadratic')
 4     try:
 5         a,b,c=eval(input("please enter the coefficients(a,b,c)\n"))
 6         discroot=math.sqrt(b*b-4*a*c)
 7         root1=(-b+discroot)/(2*a)
 8         root2=(-b-discroot)/(2*a)
 9         print("the solutions are:",root1,root2)
10     except ValueError as exc0bj:
11         if str(exc0bj)=="math domain error":
12             print("No real roots")
13         else:
14             print("you didn't give me the right number of codfficients")
15     except NameError:
16         print("you didn't enter three numbers")
17     except TypeError:
18         print("you input was not the correct form")
19     except:
20         print("some thing went trong")
21     
22 main()

 1 import math
 2 import time
 3 import random
 4 
 5 def main():   
 6     try:
 7 #        a,b,c,d=eval(input("enter four numbers:\n"))
 8         a,b,c,d=random.randint(1,100),random.randint(1,100),random.randint(1,100),random.randint(1,100)
 9         print(a,b,c,d)
10         max=a
11         time.clock()
12         if max<b:
13             max=b
14         if max<c:
15             max=c
16         if max<d:
17             max=d
18         print("max=",max)
19     except:
20         print("wrong")
21     print("time is ",time.clock())
22 main()

 1 import math
 2 import time
 3 import random
 4 
 5 def main():   
 6     try:
 7         a,b,c,d=eval(input("enter four numbers:\n"))
 8         print(a,b,c,d)
 9         max=a
10         time.clock()
11         if max<b:
12             max=b
13         elif max<c:
14             max=c
15         elif max<d:
16             max=d
17         print("max=",max)
18     except:
19         print("wrong")
20     print("time is ",time.clock())
21 main()

 1 import math
 2 import time
 3 import random
 4 
 5 def main():   
 6     try:
 7         a,b,c,d=random.randint(1,100),random.randint(1,100),random.randint(1,100),random.randint(1,100)
 8         print(a,b,c,d)
 9         print("max=",max(a,b,c,d))
10     except:
11         print("wrong")
12     print("time is ",time.clock())
13 main()

 1 from math import *
 2 from random import *
 3 
 4 def main():
 5     try:
 6         a=randint(50,100)
 7         print(a)
 8         if a>90:
 9             print("优秀")
10         elif a>80:
11             print("良好")
12         elif a>70:
13             print("一般")
14         elif a>=60:
15             print("合格")
16         else:
17             print("不合格")
18     except:
19         print("出错")
20      
21 main()

from math import *
from random import *

def main():
    try:
        a=randint(50,100)
        print(a)
        if a>=90:
            print("优秀")
        if a>=80 and a<90:
            print("良好")
        if a>=70 and a<80:
            print("一般")
        if a>=60 and a<70:
            print("合格")
        if a<60:
            print("不合格")
    except:
        print("出错")
     
main()

 1 from math import *
 2 from random import *
 3 
 4 def main():
 5     try:
 6         n=eval(input('数字个数：'))
 7         sum=0
 8         for i in range(n):
 9             num=randint(0,100)
10             print(num)
11             sum=sum+num
12         print("平均值为：",sum/n)
13     except:
14         print("运行出错")
15 main()

1 import math
2 num=0
3 while num<10:
4     num=num+1
5     if num%2==0:
6         print("find an even number",num)
7         continue
8     print("find a number",num)
9     

 1 import math
 2 def main():
 3     n=eval(input("输入素数范围："))
 4     for x in range(2,n):
 5         for i in range(2,x):
 6             if x%i==0:
 7                 break
 8         else:
 9             print(x,"是素数")
10 main()