Coding Notes

1.3 Input

2 min readAndreas PatuzziAuroville Institute of Applied Technology

Summary

  • input(): Waits for user input and always returns it as a string.
  • Prompting: Can take a string argument to display as a prompt before taking input.

Standard Usage

Python uses the function input() to get console input from the user. It will wait for the user to input something on the console. As soon as the user presses Enter the function will return the value entered by the user and continue with the program.

Input will always return the value as string. If you need the input to be a different datatype, you have to explicitly convert it. But you have to be careful, because taking input that has an unexpected datatype or datatype is one of the most common error cases. If you take input you should tell the user what you expect, check if the entered value is valid, and include exception handling.

input()

You can use the value returned by input directly or store it in a variable to use it later/multiple times.

# direct usage
print("1 The user entered the value:", input()) # -> 1 The user has entered the value {?}
 
# store in variable and use later
x = input()
print("2 The user entered the value:", x) # -> 2 The user has entered the value {?}

Prompt

The input() function can take one argument that will outputted directly before taking input. This is usually used to ask and inform the user what input is expected.

x = input("Please input a number: ")     # -> Please input a number: 
print("The user entered the number:", x) # -> The user has entered the number {?}

Questions

  • Explain input() in your own words.
  • What does the input() function always return, regardless of the type of input?
  • How can you store the value returned by input() for later use?
  • What argument can you give to input(), what does it do, and what is it usually used for?
  • Modify the code to ask the user for their name and greet them with a personalized message.
  x = input()  
  print("x: ", x)

Graph View