Data Types

Data type specifies the type of value a variable requires to do various operations without causing an error. By default, python provides the following built-in data types:

Numeric data: int, float, complex

int: 3, -8, 0

float: 7.349, -9.0, 0.0000001

complex: 6 + 2i

more on numeric data types in the number chapter.

 

Text data: str

str: “Hello World!!!”, “Python Programming”

 

Boolean data:

Boolean data consists of values True or False.

 

Sequenced data: list, tuple, range

list: A list is an ordered collection of data with elements separated by a comma and enclosed within square brackets. Lists are mutable and can be modified after creation.

Example:

list1 = [8, 2.3, [-4, 5], ["apple", "banana"]]
print(list1)

Output:

[8, 2.3, [-4, 5], ['apple', 'banana']]

 

tuple: A tuple is an ordered collection of data with elements separated by a comma and enclosed within parentheses. Tuples are immutable and can not be modified after creation. 

Example:

tuple1 = (("parrot", "sparrow"), ("Lion", "Tiger"))
print(tuple1)

Output:

(('parrot', 'sparrow'), ('Lion', 'Tiger'))

 

range: returns a sequence of numbers as specified by the user. If not specified by the user then it starts from 0 by default and increments by 1.

Example:

sequence1 = range(4,14,2)
for i in sequence1:
    print(i)

Output:

4
6
8
10
12

 

Mapped data: dict

dict: a dictionary is an unordered collection of data containing a key:value pair. The key:value pairs are enclosed within curly brackets.

Example:

dict1 = {"name":"Maxon", "age":25, "canVote":True}
print(dict1)

Output:

{'name': 'Maxon', 'age': 25, 'canVote': True}

 

Binary data: bytes, bytearray, memoryview

bytes: bytes() function is used to convert objects into byte objects, or create empty bytes object of the specified size.

Example:

#Converting string to bytes
str1 = "This is a string"
arr1 = bytes(str1, 'utf-8')
print(arr1)
arr2 = bytes(str1, 'utf-16')
print(arr2)

#Creating bytes of given size
bytestr = bytes(4)
print(bytestr)

Output:

b'This is a string'
b'\xff\xfeT\x00h\x00i\x00s\x00 \x00i\x00s\x00 \x00a\x00 \x00s\x00t\x00r\x00i\x00n\x00g\x00'
b'\x00\x00\x00\x00'

 

bytearray: bytearray() function is used to convert objects into bytearray objects, or create empty bytearray object of the specified size.

Example:

#Converting string to bytes
str1 = "This is a string"
arr1 = bytearray(str1, 'utf-8')
print(arr1)
arr2 = bytearray(str1, 'utf-16')
print(arr2)

#Creating bytes of given size
bytestr = bytearray(4)
print(bytestr)

Output:

bytearray(b'This is a string')
bytearray(b'\xff\xfeT\x00h\x00i\x00s\x00 \x00i\x00s\x00 \x00a\x00 \x00s\x00t\x00r\x00i\x00n\x00g\x00')
bytearray(b'\x00\x00\x00\x00')

 

memoryview: memoryview() function returns a memory view object from a specified object.

Example:

str1 = bytes("home", "utf-8")
memoryviewstr = memoryview(str1)
print(list(memoryviewstr[0:]))

Output:

[104, 111, 109, 101]

 

Set data:

Set is an unordered collection of elements in which no element is repeated. The elements of sets are separated by a comma and contained within curly braces.

Example:

set1 = {4, -5, 8, 3, 2.9}
print(set1)

Output:

{2.9, 3, 4, 8, -5}

 

None:

None is used to define a null value. When we assign a None value to a variable, we are essentially resetting it to its original empty state which is not the same as zero, an empty string or a False value.

Example:

state = None
print(type(state))

Output:

<class 'NoneType'>