User Input

Getting Input From the Shell

we can prompt the user through the console / terminal / shell / command prompt
the user enters input through the same mechanism

The input() Function

There's a built-in function in Python called input …

what does it do? does it have parameter(s)? →
(how can we find out through IDLE?) →
what does it return? →
what if the user input is a number? →

input takes one parameter - the prompt that is displayed (think of it as print plus retrieving user input!)
use help! or check the docs…
it returns a string representing the user's input
it will always return a string - even if the user inputs a number

Let's Try Some Examples of input()

>>> s = input(">")
>foo
>>> type(s)
<class 'str'>
>>> x = input(">")
>5
>>> type(x)
<class 'str'>
>>> x = int(input(">"))
>5
>>> type(x)
<class 'int'>

The input function does two things:

prints out the prompt
returns the value typed in by the user back to your program

Write a Program That Asks For a Name

… and then says "hi". Here's the sample output; the text after the > is user input.

What's your name?
>Joe
Hi Joe

A potential solution… →

print("What's your name?")
name = input(">\n")
print("Hi " + name)

(note that we used newline, \n, to create a line break for the prompt that's printed out)

Write a Program That Adds Exclamation Points

Here's the sample output; the text after the > is user input.

How loudly?
>4
This is really loud!!!!