# Chapter 2: Fundamentals of python-5 Boolean

2022-01-30 12:38:29

# Python Boolean

## The goal is

In this article , You will understand Python Boolean data type 、 False and true values .

## Python Introduction to Boolean data types

In programming , You often want to check whether the condition is true , And perform some operations according to the results .

To show true and false ,Python Boolean data type is provided . Boolean values have a technical name bool.

Boolean data types have two values :`True` and `False`.

Be careful , Boolean value True and False In capital letters (T) and (F) start .

The following example defines two Boolean variables :

``````is_active = True
Copy code ``````

When you compare two numbers ,Python The result will be returned as a Boolean value . for example :

``````>>> 20 > 10
True
>>> 20 < 10
False
Copy code ``````

Again , Comparing two strings yields a Boolean value :

``````>>> 'a' < 'b'
True
>>> 'a' > 'b'
False
Copy code ``````

## bool() function

To determine a value is `True` still `False`, have access to `bool()` function . for example :

``````>>> bool("Hi")
True
>>> bool (' ')
False
>>> bool(100)
True
>>> bool(0)
False
Copy code ``````

It is clear from the output that , Some values are calculated as True, Other values are calculated as False.

## False and true values

When a value is calculated as `True` when , It's true . If a value equals `False`, It's fake .

Here are Python False values in :

• Numbers 0(`0`)
• An empty string `' '`
• `False`
• `None`
• An empty list `[]`
• An empty tuple `()`
• An empty dictionary `{}`

True values are other true values .

summary

• Python Boolean data types have two values :True and False.
• Use bool() Function to test a value is True still False.
• The false value is calculated as False, The true value is calculated as True.
• False values are numbers 0、 An empty string 、False、None、 An empty list 、 Empty tuples and empty dictionaries . True value is not false value .