# Lesson 3b - Booleans

Booleans are one of the simplest data types. It consists entirely of “True” and “False”.

## Table of Contents

## Lesson Objectives

- Learn what booleans are.
- Use boolean operators.
- Compare numerical values.

## What’s a Boolean?

Named after George Boole, a boolean is a value that is either true or false. It’s most commonly used in logic. In Python, it’s useful for creating conditional statements and loops, which we’ll talk about in lesson 4.

## Creating a Boolean Value

In Python, declaring a boolean value is similar to declaring a number. Rather than using a numerical constant, you need to use `True`

or `False`

.

Make sure `True`

and `False`

are capitalized!

Input

```
a = True
print(type(a))
```

Output

```
<class 'bool'>
```

## Boolean Operators

Just like integers and floats, booleans have their own set of algebraic rules known as Boolean Algebra.

The three most common operations are listed in the table below.

Boolean Operator | Keyword |
---|---|

AND | and |

OR | or |

NOT | not |

### AND

The AND operator results in True if both booleans are already True. Otherwise, it becomes False.

Input

```
a = True
b = True
c = False
print(a and b)
print(a and c)
```

Output

```
True
False
```

### OR

The OR operator results in True if at least one boolean is True. Otherwise, it becomes False.

Input

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

Output

```
True
False
```

### NOT

The NOT operator reverses the current value. True becomes False, and False becomes True.

Input

```
a = True
c = False
print(not a)
print(not c)
```

Output

```
False
True
```

## Order of Logical Operations

Just like regular algebra, booleans have their own order of operations. The order is listed in the table below. Operations at the top have higher precedence.

Logical Operator | Keyword |
---|---|

Brackets | ( ) |

NOT | ! |

AND | & |

OR | | |

## Numerical Comparisons

We can also compare the values of expressions to generate a boolean as well.

The six comparison operators are shown in the table below.

Comparison | Symbol |
---|---|

Less than | < |

Less than or equal | <= |

Greater than | > |

Greater than or equal | >= |

Equality | == |

Inequality | != |

Input

```
print(5 < 8)
print(2 < 1)
print(3 == 3.0)
```

Output

```
True
False
True
```

## Key Points / Summary

- A boolean is a True/False value.
`and`

,`or`

, and`not`

are three boolean operators.- You can compare numerical values.