Python basic while loop and if judgment, python basic whileif

Python basic while loop and if judgment, python basic whileif

　Wlile Loop

While True indicates that it is always True. No matter what conditions, it will be executed downward. Below is an example of writing.

#! /Usr/bin/env pythonage = 24 # assign a value to age while True: # enter The loop inputting = int (input ("The input number is :")) # Save the user output to the variable inputting if inputting = age: # Compare print ("Guessed it !!! ")
Break if inputting <age: print ("Is to small !!! ") Else: print (" Is to big !!! ")

Write a user-friendly example. In the above example, all the conditions of while True are True. In the following example, You can execute the following code only when the conditions are met. In the following example, after you enter three times, the system will tell you whether to continue after the input times are too many. Press yes to exit and Press no.

#! /Usr/bin/env pythonage = 24 count = 0 # counter while count <3: # The count value is less than 0 to execute the following code. Inputting = int (input ("The input number is:") # Save The user output to The inputting variable. int is The data type. If inputting = age: print ("Guessed it !!! ") # Compare the value of the variable to break # if the output value Is equal to the value of age, print the output, and then destroy the loop if inputting <age: print (" Is to small !!! ") Else: print (" Is to big !!! ") Count + = 1 # Add a while count = 3 every cycle: # If count is equal to 3, run the following code warning = input (" Whether or not to continue? (Yes no) ") # The warning message is displayed, and the user output value is included in the if warning = 'no': # destroy the loop by no, yes continue count reset returns the first loop. Other returns let you enter the information break elif warning = 'yes': count = 0 else: print ("yes or no ")

If judgment

As the name suggests, "if" is just what it is. In the following example, the if statement is used. if the user name and password are correct, the welcome information is displayed. if the user name and password are incorrect, a message is displayed, indicating that the user name and password are incorrect. Of course, continuous input can be associated with the above while loop.

#! /Usr/bin/env pythonusername = input ("username:") password = input ("password:") _ username = ("admin ") # store the username and password in _ username and _ password = ("abc") if username = _ name and password = _ password: # print ("Welcome {name} login .... ". format (name = username) # {name} is a placeholder. format indicates his real identity. Else: print ("Invalid username password ")