3.4. How the input() functions works

The text "Write something: " inside the input is called the instruction.

Writing Clear Instructions

Each time you use the input() function, you should include an easy-to-follow instruction. See the example.

Sometimes you'll want to write a longer instruction. See the example.

This example shows one way to build a multi-line string. The operator += takes the string that was assigned to instruction and adds the new string onto the end.

Using int() to Accept Numerical Input

When you use the input() function, every input will be seen as a string. To input an integer, you can use the int() function, which tells Python to interpret the input as a numerical value. Try to delete line 2 in the example and see what will happen:

The modulo operator

One useful tool when working with numbers is the modulo operator (%). This operator divide one number by another number then returns the remainder:

When one number is divisible by another number, the remainder is 0, so the modulo operator always returns 0. Module operator frequently use to tell even or odd number.

In the example, even numbers are always divisible by two, so if the modulo of a number and two is zero (here, if number % 2 == 0) the number is even. Otherwise, it's odd.