If Operations
Checkpoint #1
Whitespace
Elif
Checkpoint #2
Nested If
Summary
Nested If
If Statements can be stacked one after another as you have seen in previous examples, but it is also possible for If Statements to be nested within a parent If Statement. Let's look at an example below:
1 operation = "division"
2 number1 = 9
3 number2 = 3
4 if operator == "division":
5 if number2 == 0:
6 print("You cannot divide by zero")
7 else:
8 print(number1 / number2)
9 elif operator == "multiplication":
10 print(number1 * number2)
The first If Statement checks to determine if the operation is division. If so, then there is a secondary check to determine if the denominator (number2 in this case) is zero.
Now let's have you try. Let's complete this calculator by adding addition and subtraction. But our calculator has two special requirements:

The two variables (number1 and number 2) should always be positive

The result of any calculation should never be less than zero (HINT: watch out for subtraction)
If either of these rules are violated, the calculator should print: "This operation is not allowed"