The operators that are used in Python programming to assign values are listed in the presentation of this lecture. All except the simple = assignment operator are a shorthand form  of a longer expression, so each equivalent is given for clarity:

The += operator is useful to add value onto an existing value that is stored in a variable.

In the table example, the += operator first adds the value contained in variable a to the value contained in variable b. It then assigns the result to become the new value stored in variable a.

All the other operators work in the same way by making the arithmetical operation between the two values first, then assigning the result of that operation to the first variable – to become its new stored value.

With the %= operator, the first operand a is divided by the second operand b, then the remainder of that operation is assigned to a variable.