Python if while

1. If format

>>> 1<3

True True
>>> 1>3
False false

If condition: Condition +:

(tab) Execution statement

(tab) Execute Statement Front tab for if condition execution Trun (TRUE)

.....

Else

(tab) Execution statement execution false (false)

.......

Determine if the input number is 8

1 Print('Hi')2temp= input ("Number ?")3guess=Int (temp)4 ifGuess==8:5     Print("Yes")6 Else:7     Print(" on")8 Print(" the")9     

Add Size tip Note indent

1 Print('Hi')2temp= input ("Number ?")3guess=Int (temp)4 ifGuess==8:5     Print("Yes")6 Else:7     ifGuess>8:8      　　 Print("+")9     Else:Ten      　　 Print("-") One Print(" the") A     

2.while

While condition:

Execute when condition is true (true)

Limit times

1 Print('Hi')2temp= input ("Number ?")3guess=Int (temp)5  whileGuess! = 8:6temp= input ("NoNoNo")7guess=Int (temp)8     ifGuess = = 8:9         Print("Yes")Ten     Else: One         ifGuess>8: A             Print("+") -         Else: -             Print("-") - Print(" the")

3. And OR

A line in Python3 can write multiple statements, separated by ";".

Lift example: a = 4;c = 5

A statement in Python3 can be divided into multiple lines of writing, using a backslash ' \ ' or using parentheses to break up into several lines

Print (' I love \

Python ')

Or

>>> (I Love and

Python)

Print\

("HH")

Random number requires random module, Random.randint (A, A, b)

Give users three chance to try, run out of opportunities or user guess answers all exit loops

1 ImportRandom2Times = 33Secret = Random.randint (1,5)  4 Print("--------Welcome to guessing the numbers game--------\ n")  5Guess =06 Print("guess which value in 1-5? :", end=" "Print prints a line by default and ends with a newline. End= "" means the end does not wrap, plus a space7  while(Guess! = secret) and(Times >0):8Guess =int (input ()) is the same as C's scanf and does not output a string9Times = Times-1Ten     ifGuess = =Secret: One         Print("\ n Guess right, why are you so interested?!! \ n")   A         Print("but there's no reward for guessing.")   -     Else:   -         ifGuess >Secret: the             Print("It's big, ~\n.")   -         Else:   -             Print("Oh, little ~\n.")   -         ifTimes >0: +             Print("Try one more time:", end=" ")   -         Else:   +             Print("3 times the chance is exhausted! ~\n")   A Print("game over, don't play ^_^ \ n")

1 Print ('--------print a list of numbers-----------') 2 tmp = input (' Please enter a number:')3 num = int (tmp)4 i = 15 while num:6     print(i)7      i = i + 18     num = num-1

Run results, enter 5

--------Print a list of numbers-----------

Please enter a number: 5

1

2

3

4

5

1 Print('--------Print a set of symbols-----------')2TMP = input ('Please enter the number of groups:')3Fuhao = input ('Please enter a symbol:')4num =INT (TMP)5  whileNum:6     Print(' '* num + Fuhao *num) repeats num times spaces with num times symbols7num = num-1

--------print a set of symbols-----------
Please enter the number of groups: 3
Please enter a symbol: 0
000
00
0

Write a program that determines whether a given year is a leap years.

1temp = input ('Please enter a year:')2  while  nottemp.isdigit ():3temp = input ("Sorry, your input is wrong, please enter an integer:")4 5Year =Int (temp)6 ifyear/400 = = Int (year/400):7     Print(temp +'is a leap year! ')8 Else:9     if(YEAR/4 = = Int (YEAR/4)) and(year/100! = Int (year/100)):Ten         Print(temp +'is a leap year! ') One     Else: A         Print(temp +'not a leap year! ')

Python if while