6.1. Updating variables

Commonly, assignment statements are used to update a variable, where the new value of the variable depends on the old.

x = x + 1

This means “get the current value of x, add 1, and then update x with the new value.”

If you try to update a variable that doesn’t exist, you get an error, because Python evaluates the right side before it assigns a value to x:

Before you can update a variable, you have to initialize it, usually with a simple assignment:

When you update a variable by adding 1 it’s called an increment; subtracting 1 is called a decrement.

You have attempted of activities on this page