Python has three Boolean operators, or logical operators: and
, or
, and not
. You can use them to check if certain conditions are met before deciding the execution path your programs will follow. In this tutorial, you’ll learn about the and
operator and how to use it in your code.
In this tutorial, you’ll learn how to:
- Understand the logic behind Python’s
and
operator - Build and understand Boolean and non-Boolean expressions that use the
and
operator - Use the
and
operator in Boolean contexts to decide the course of action of your programs - Use the
and
operator in non-Boolean contexts to make your code more concise
You’ll also code a few practical examples that will help you understand how to use the and
operator to approach different problems in a Pythonic way. Even if you don’t use all the features of and
, learning about them will allow you to write better and more accurate code.
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Working With Boolean Logic in Python
Back in 1854, George Boole authored The Laws of Thought, which contains what’s known as Boolean algebra. This algebra relies on two values: true and false. It also defines a set of Boolean operations, also known as logical operations, denoted by the generic operators AND
, OR
, and NOT
.
These Boolean values and operators are pretty helpful in programming. For example, you can construct arbitrarily complex Boolean expressions with the operators and determine their resulting truth value as true or false. You can use the truth value of Boolean expressions to decide the course of action of your programs.
In Python, the Boolean type bool
is a subclass of int
and can take the values True
or False
:
>>> issubclass(bool, int)
True
>>> help(bool)
Help on class bool in module builtins:
class bool(int)
...
>>> type(True)
<class 'bool'>
>>> type(False)
<class 'bool'>
>>> isinstance(True, int)
True
>>> isinstance(False, int)
True
>>> int(True)
1
>>> int(False)
0
As you can see in this code, Python implements bool
as a subclass of int
with two possible values, True
and False
. These values are built-in constants in Python. They’re internally implemented as integer numbers with the value 1
for True
and 0
for False
. Note that both True
and False
must be capitalized.
Along with the bool
type, Python provides three Boolean operators, or logical operators, that allow you to combine Boolean expressions and objects into more elaborate expressions. Those operators are the following:
With these operators, you can connect several Boolean expressions and objects to build your own expressions. Unlike other languages, Python uses English words to denote Boolean operators. These words are keywords of the language, so you can’t use them as identifiers.
In this tutorial, you’ll learn about Python’s and
operator. This operator implements the logical AND
operation. You’ll learn how it works and how to use it either in a Boolean or non-Boolean context.
Getting Started With Python’s and
Operator
Python’s and
operator takes two operands, which can be Boolean expressions, objects, or a combination. With those operands, the and
operator builds more elaborate expressions. The operands in an and
expression are commonly known as conditions. If both conditions are true, then the and
expression returns a true result. Otherwise, it returns a false result:
>>> True and True
True
>>> False and False
False
>>> True and False
False
>>> False and True
False
These examples show that an and
expression only returns True
when both operands in the expressions are true. Since the and
operator takes two operands to build an expression, it’s a binary operator.
The quick examples above show what’s known as the and
operator’s truth table:
operand1 |
operand2 |
operand1 and operand2 |
---|---|---|
True | True | True |
True | False | False |
False | False | False |
False | True | False |
This table summarizes the resulting truth value of a Boolean expression like operand1 and operand2
. The result of the expression depends on the truth values of its operands. It’ll be true if both are true. Otherwise, it’ll be false. This is the general logic behind the and
operator. However, this operator can do more than that in Python.
In the following sections, you’ll learn how to use and
for building your own expressions with different types of operands.
Using Python’s and
Operator With Boolean Expressions
You’ll typically use logical operators to build compound Boolean expressions, which are combinations of variables and values that produce a Boolean value as a result. In other words, Boolean expressions return True
or False
.
Read the full article at https://realpython.com/python-and-operator/ »
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