Reading input
while loops can have conditions that are always satisfied. Those programs will result in an infinite loop and will run forever. A good example of that type of program is while True:while True:
print('Welcome to an infinite loop!')This program will run forever and will print
Welcome to an infinite loop! until it’s stopped by the user.while loops can be used to read data until some condition has been met. For instance, we can read the data from the input while the input is not 0. As soon as the user inputs a 0 and hits enter, the while loop should end. This can be implemented as:num = -1
while num != 0:
num = int(input())
print(f'The user entered: {num}')
print('End!')This program will read the input as long as the user hasn’t entered 0, and as soon as the user enters 0, it will get out of the loop and print
End!.We can even read the
num beforehand and then start the loop:num = int(input())
while num != 0:
print(f'The user entered: {num}')
num = int(input())
print('End!')This way, the program won’t print the final
0 as it will get out of the loop before that. You can try it yourself to play around with those two ways.
Challenge
Write a program that reads the input until reaching a word
End and prints the inputted text to the output. As soon as the program reaches the word End it should stop. The program should not print the final End from the input.Input | Output |
hello
my
name
End | hello
my
name |
Constraints
Time limit: 2 seconds
Memory limit: 512 MB
Output limit: 1 MB