Introduction to Data Type

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∟Introduction to Data Type

This section provides a quick introduction of Python basic data types including NoneType, bool, int, float, bytes, str, tuple, list, dict, etc.

What Is Data Type? A data type is defined as a class of data objects who shares the same data structure, properties and operations.

There are two very important statements about Python you should remember:

All data in a Python program is represented by objects.
Every object has an identity, a type and a value.

You can use the type(object) function to see the class name that defines the given data object:

>>> type(314)
<class 'int'>

>>> type(3.14)
<class 'float'>

>>> type('3.14')
<class 'str'>

>>> type(True)
<class 'bool'>

>>> type(None)
<class 'NoneType'>

>>> type(())
<class 'tuple'>

>>> type([])
<class 'list'>

>>> type({})
<class 'dict'>

>>> type(type)
<class 'type'>

>>> type(exit)
<class '_sitebuiltins.Quitter'>

Python data types can be grouped into hierarchical trees as shown below (devopedia.org):

In this chapter, we will cover the following basic data types:

NoneType - A data type with a single null object.
bool - A data type with 2 objects: True and False.
int - A data type used to store a single integer.
float - A data type used to store a single real number.
bytes - A data type used to store a sequence of bytes.
str - A data type used to store a sequence of characters.
tuple - A data type used to store an immutable and ordered collection of data objects.
list - A data type used to store a mutable and ordered collection of data objects.
dict - A data type used to store a collection of key-value pairs.