006 operator introduction

One 、 Mind mapping

Two 、 Knowledge and examples

1、a=a+3 Equate to a+=3;a=a3 Equate to a=3

2、“/” True division ;“//” Rounding Division

Example ：10\3=3.33333;10//3=3

3、 Square operation

32=9 It's Square 2 Time
3***5 It's Square 5 Time

4、 Examples of remainder operations ：

5%2 Represents the remainder result =1

5、 Logic short circuit phenomenon of logic operation symbols

Please say the answer as fast as you can ：not 1 or 0 and 1 or 3 and 4 or 5 and 6 or 7 and 8 and 9
answer ：4
reason ： stay python in , Logical operators or,x or y, If x by True Then return to x, If x by False return y value . Because if x by True that or There is no need to calculate , Because if one is true, it is true , So back x Value . If x The value of is false , that or The result of the operation depends on y, So back y Value .
** stay python in , Logical operators and,**x and y, If x by True Then return to y value . If x by False Then return to y value . If x The value of is True,and The operation of will not end , Will continue to watch y Value , So at this time, true or false depends on y Value , therefore x If it is true , Then return to y Value . If x For false , that and The operation will end , Because one is false and For false , So back x Value .

3、 ... and 、 In class code

Four 、 After-school exercises

1、 Improve our games ： When the user enters the wrong type , Prompt the user to re-enter , Prevent the program from crashing .

print('***** i love cjy *****')
a=input('hi, Guess how many hours I slept last night \n')
while a.isdigit ()!=True:
   a= input('please input a int number\n')
if int(a)==9:
    print(' You guessed it , But I haven't slept enough ')
else:
    print(' I sleep   How long have you been unable to count ？ Don't care about me at all , idot ！！！ Stupid stupid \n' )       
print(' Game over , Play something different next time ')

2、 Write a program , Determine whether a given year is a leap year .

a=input('please input a year: ')
year=int(a)
if (year%4==0 and year%100!=0) or (year%400==0):
    print('this is a leap year ')
else:
    print('this is a not a leap year')

3、 Set up printing 1-100 Base number of

Code ：

for i in range(1,101):
    if i%2!=0:
        print(i)
    i+=1

Mistakes that have happened ：
stay for Forget to use after the cycle ’：‘ 了