Boolean Operators

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Python also includes several operators that can be applied to one or two Boolean values. These operators make up the basis of Boolean logic, and allow us to construct complex expressions of Boolean values. Let’s quickly review the three basic Boolean operators present in Python.

And Operator

In Python, we use the keyword and to perform the Boolean and operation. This operator will return True if both input values are also True, otherwise it will return False.

This corresponds to the following truth table:

Here’s a quick example of the and operator in Python:

x = True
y = False
print(x and y)

When we run this Python code, we should see this output:

False

Since the variable y is False, the resulting value is also False.

Or Operator

Likewise, the keyword or is used in Python for the Boolean or operation. This operator will return True if either of the input values is True, but it will return False if neither of them are True.

This corresponds to the following truth table:

Let’s look at an example:

a = False
b = True
print(a or b)

When we execute this code, we’ll get this output:

True

Since b is True, we know that at least one input is True and the result of a or b is also True.

Not Operator

Finally, Python uses the keyword not to represent the Boolean not operation, which simply inverts a Boolean value from True to False and vice-versa.

This corresponds to the following truth table:

Here’s an example:

x = True
print(not x)
print(not not x)

When we run this code, we’ll see this printed to the terminal:

False
True

Since x is True, we know that not x is False. We can then perform the not operation again, on that result, as shown in not not x, which will result in the original value of x, which is True.