Comprehensive Guide on Python Data types with Examples

Introduction

Python is a versatile and powerful language that offers a multitude of possibilities for application development. Whether you are interested in system administration, building GUI programs, creating database applications, or even scripting, Python has got you covered. One of the critical strengths of Python lies in its extensive collection of data types, which enables efficient and effective implementation of a wide range of applications. In this article, we will delve into the fundamental data types of Python and explore their built-in functions. By understanding these data types and their functionalities, you will unlock the full potential of Python.

This article was published as a part of the Data Science Blogathon

What are Data Types in Python?

Data types in Python refer to classifying or categorizing data objects based on their characteristics and behavior. They define the type of values variables can hold and determine the performed operations on those values. Python has several built-in data types, including numeric types (int, float, complex), string (str), boolean (bool), and collection types (list, tuple, dict, set). Each data type has its own set of properties, methods, and behaviors that allow programmers to manipulate and process data effectively in their programs.

Built-in Data Types in Python

Built-in data types in Python are fundamental data structures provided by the Python programming language. They are pre-defined and available for use without requiring any additional libraries or modules. Python offers several built-in data types, including:

1. Numeric Data Types: Numeric data types in Python are used to represent numerical values. Python provides three primary numeric data types:
   • Integer (int): Integers are whole numbers without any decimal points. They can be positive or negative.
   • Floating-Point (float): Floating-point numbers represent decimal values. They can be positive or negative and may contain a decimal point.
   • Complex (complex): Complex numbers are used to represent numbers with a real and imaginary part. They are written in the form of a + bj, where a is the real part and b is the imaginary part.
2. String Data Type(str): Represents a sequence of characters enclosed in single quotes (‘ ‘) or double quotes (” “), such as “Hello, World!”, ‘Python’.
3. Boolean Data Type(bool): Represents either True or False, used for logical operations and conditions.
4. Collection Data Types:
   • list: Represents an ordered and mutable collection of items, enclosed in square brackets ([]).
   • tuple: Represents an ordered and immutable collection of items, enclosed in parentheses ().
   • dict: Represents a collection of key-value pairs enclosed in curly braces ({}) with unique keys.
   • set: Represents an unordered and mutable collection of unique elements, enclosed in curly braces ({}) or using the set() function.

Numeric Data Types

Numeric data types in Python are used to represent numerical values. Python provides three primary numeric data types – integer (int), floating-Point (float) and complex (complex). These numeric data types allow for performing various arithmetic operations, such as addition, subtraction, multiplication, and division. They provide the necessary flexibility to work with numerical data in Python programs.

• Int – It stores the integers values that can be positive or negative and do not contain any decimal point. Example: num1=10, num2 = 15
• Float – These are floating-point real numbers that stores the decimal values. It consists of integer and fraction parts. Example: fnum = 25.4, fnum1=67.8
• Complex – These are complex numbers specified as a real part and an imaginary part. They are stored in the form of a + bj where a is the real part and j represents the imaginary part. Example: num3= 2 + 3j, numcom = 5 – 7j

Python Code:

Integers (int)

Python’s integer data type (int) represents whole numbers without any decimal points. It stores positive and negative whole numbers. Integers are immutable, meaning their value cannot be changed once assigned.

Example 1

# Assigning integer values to variables

x = 5

y = -10

# Performing arithmetic operations

sum_result = x + y

difference_result = x - y

multiplication_result = x * y

division_result = x / y

# Printing the results

print("Sum:", sum_result)

print("Difference:", difference_result)

print("Multiplication:", multiplication_result)

print("Division:", division_result)

Output:

Sum: -5

Difference: 15

Multiplication: -50

Division: -0.5

Example 2

# Using integer values in comparisons

a = 10

b = 20

# Comparing the values

greater_than = a > b

less_than_or_equal = a <= b

equal_to = a == b

not_equal_to = a != b

# Printing the results

print("Greater than:", greater_than)

print("Less than or equal to:", less_than_or_equal)

print("Equal to:", equal_to)

print("Not equal to:", not_equal_to)

Output:

Greater than: False

Less than or equal to: True

Equal to: False

Not equal to: True

Floating-Point Numbers (float)

The float data type in Python is used to represent floating-point numbers, which are numbers with decimal points. Floats are used when more precision is needed than what integers can provide. Floats are immutable like integers and follow the IEEE 754 standard for representing real numbers.

Example 1

# Assigning float values to variables

x = 3.14

y = 2.5

# Performing arithmetic operations

sum_result = x + y

difference_result = x - y

multiplication_result = x * y

division_result = x / y

# Printing the results

print("Sum:", sum_result)

print("Difference:", difference_result)

print("Multiplication:", multiplication_result)

print("Division:", division_result)

Output:

Sum: 5.64

Difference: 0.64

Multiplication: 7.85

Division: 1.256

Example 2

# Using float values in comparisons

a = 1.2

b = 2.7

# Comparing the values

greater_than = a > b

less_than_or_equal = a <= b

equal_to = a == b

not_equal_to = a != b

# Printing the results

print("Greater than:", greater_than)

print("Less than or equal to:", less_than_or_equal)

print("Equal to:", equal_to)

print("Not equal to:", not_equal_to)

Output:

Greater than: False

Less than or equal to: True

Equal to: False

Not equal to: True

Complex Numbers (complex)

The complex data type in Python is used to represent numbers with both real and imaginary parts. It is written in the form of a + bj, where a represents the real part and b represents the imaginary part. Complex numbers are useful in mathematical calculations and scientific computations that involve imaginary quantities.

Example 1

# Assigning complex values to variables

x = 2 + 3j

y = -1 + 2j

# Performing arithmetic operations

sum_result = x + y

difference_result = x - y

multiplication_result = x * y

division_result = x / y

# Printing the results

print("Sum:", sum_result)

print("Difference:", difference_result)

print("Multiplication:", multiplication_result)

print("Division:", division_result)

Output:

Sum: (1+5j)

Difference: (3+1j)

Multiplication: (-8+1j)

Division: (0.8-1.4j)

Example 2

# Using complex values in comparisons

a = 1 + 2j

b = 3 + 4j

# Comparing the values

equal_to = a == b

not_equal_to = a != b

# Printing the results

print("Equal to:", equal_to)

print("Not equal to:", not_equal_to)

Output:

Equal to: False

Not equal to: True

Textual Data Types – Strings

Textual data types in Python are used to represent and manipulate sequences of characters, such as words, sentences, or even larger blocks of text. The primary textual data type in Python is the string (str). Strings are enclosed in quotes (‘ ‘, ” “, or “”” “””) and can be manipulated using various string methods. They are immutable, meaning their values cannot be changed once assigned. String data types are commonly used for tasks like text processing, input/output operations, and data manipulation.

Accessing String Values

Each character of a string can be expressed with the help of a technique called indexing. In indexing, each character has an index value represented by either a positive or negative integer starting from 0.

Syntax:- stringname[index]

Example

Str1=”Python
#accessing second character 
Str1[1]
#accessing first four characters
Str1[0:4]  # it will print the value from index 0 to 3
str1="Python"
>>> str1[1]
'y'
>>> str1[0:4]
'Pyth'

String Operations

1) Concatenation – Python allows us to join two different strings using the concatenation operator ‘+’ 

Syntax:– str1 + str2

Example

>>> str1="Analytic"
>>> str2="Vidya"
>>> str3=str1 +str2
>>> print(str3)
AnalyticVidya

2) Repetitions – Python allows us to repeat a given string with the help of ‘ * ‘ operator.

Syntax:– stringname * integervalue

Example

>>> str2 = "python"
>>> str2 * 3
'pythonpythonpython'

3) Membership – The Membership operator helps to check whether a given character is present in the string or not with the help of two operators in and not in. In and not in operator returns the boolean value True or False.

Syntax:– character in/not in stringname

Example

>>> str1="python"
>>> "p" in  str1
True
>>> "f" in str1
False

Built-in Functions in String

1) Len() – It is used to calculate the length of the given string.

Syntax:– len(stringname)

Example

>>> str1="Python"
>>> len(str1)
6

2) isupper() – This function is used to check whether all the letters in a string are in the upper case or not. If all the characters are in upper case then it returns True otherwise it returns False.

Syntax:– stringname.isupper()

Example

>>>str1= " Hello Everyone"
>>> str1.isupper()
False
>>> str2="HELLO"
>>> str2.isupper()
True

3) islower() – This function is used to check whether all the letters in a string are in lowercase or not. If all the characters are in lower case then it returns True otherwise it returns False.

Syntax:– stringname.islower()

Example

>>> s="hello"
>>> s.islower()
True
>>> s1="hey Folks!"
>>> s1.islower()
False

4) upper() – It is used to convert all the characters of a string in uppercase.

Syntax:– stringname.upper()

Example

>>>str1= " Hello Everyone"
>>> str1.upper()
' HELLO EVERYONE'

5) lower() – It is used to convert all the characters of a string in lowercase.

Syntax:– stringname.lower ()

Example

>>> str2="HELLO"
>>> str2.lower()
'hello'

Boolean Data Type

The boolean data type in Python represents logical values of True and False. It is used to evaluate conditions and make logical decisions in a program. Booleans are the result of comparisons and logical operations.

Example 1

# Logical operations with booleans

a = True

b = False

result_and = a and b

result_or = a or b

result_not = not a

print(result_and)

print(result_or)

print(result_not)

Output:

False

True

False

Example 2

# Comparisons using booleans

x = 5

y = 10

greater_than = x > y

less_than_or_equal = x <= y

equal_to = x == y

not_equal_to = x != y

print(greater_than)

print(less_than_or_equal)

print(equal_to)

print(not_equal_to)

Output:

False

True

False

True

Collection Data Types

Collection data types in Python are used to store and organize multiple values into a single entity. Python provides several built-in collection data types, including lists, tuples, dictionaries, and sets.

Lists (list)

The list data type in Python is used to store multiple items in a single variable. Lists are ordered, mutable, and can contain elements of different data types. They are created by enclosing comma-separated values within square brackets [ ].

Example 1

List1=[123,567,89] #list of numbers

List2=[“hello”,”how”,”are”] #list of strings

List3= [“hey”,1223,”hello”] #list of mixed data type.

Accessing Elements of the List

Elements of the list are accessed in the same as that of string that is with the help of positive and negative indexing. Slicing is also used to access the list elements in which more than a single element is accessed at a time.

List1=[“apple”,123,”mango”,[2,3,4,]]

Example

>>> list1=['apple',123,"mango",[2,3,4,]]
>>> list1[0]
'apple'
>>> list1[3]
[2, 3, 4]
>>> list1[1:3]
[123, 'mango']

Operations in List

1) Concatenation – Two lists are concatenated with the help of “+” operator.

Syntax:- list1 + list2

>>> list1=["apple","mango",123,345]
>>> list2 = ["grapes"]
>>> list1 + list2
['apple', 'mango', 123, 345, 'grapes']

2) Repititions – With the help of the ‘ * ‘ operator list can be repeated n number of times.

Syntax:- list1* number

>>> list1=["apple","mango",123,345]
>>> list1*2
['apple', 'mango', 123, 345, 'apple', 'mango', 123, 345]

3) Membership – ‘ in ‘and ‘ not in ‘ are two membership operators that are used to check whether the given element is present in the list or not and return a Boolean value True or False.

Syntax:– element in/not in in list1

>>> list1=["apple","mango",123,345]
>>> 'apple' in list1
True
>>> 'apple' not in list1
False

Built-in functions in the list

1) append() – This function is used to add a single element at the end of the list. The single element that is added can be of any data type like integer, list, string, etc.

Syntax :- listname.append(element)

>>> list1=["apple","mango","grapes",123,345]
>>> list1.append("orange")
>>> list1
['apple', 'mango', 'grapes', 123, 345, 'orange']
>>> list1.append([12,34,55])
>>> list1
['apple', 'mango', 'grapes', 123, 345, 'orange', [12, 34, 55]]

2) insert() – insert() function is also used to add element in this list but with the help of insert we can add the element at a particular index in the list. If the index is not present then it will add the element at the end of the list.

Syntax :- listname.insert (index,element)

>>> list2=["apple","mango","grapes",123,345]
>>> list2.insert(0,234)
>>> list2
[234, 'apple', 'mango', 'grapes', 123, 345]
>>> list2.insert(6,"papapa")
>>> list2
[234, 'apple', 'mango', 'grapes', 123, 345, 'papapa']

3) count() – count function is used to count the number of time an element occurs in the list.

Syntax:– listname.count(element)

>>> list3=[12,45,12,67,78,90]
>>> list3.count(12)
2
>>> list3.count(11)
0

4) reverse() – reverse function is used to reverse the order of elements in the list.

Syntax:– listname.reverse()

>>> list3=[12,45,12,67,78,90]
>>> list3.reverse()
>>> list3
[90, 78, 67, 12, 45, 12]

5) sort() – sort function is used to arrange the elements of the list in ascending order. The function list must contain all the elements in the same data type that is either integers or strings.

Syntax:– listname.sort()

list4=["grapes","banana","apple","mango"]
>>> list4.sort()
>>> list4
['apple', 'banana', 'grapes', 'mango']
>>>list5=[12,45,12,67,78,90]
>>>list5.sort()
[12,12,45,67,78,90]

Dictionary

Dictionary is a special data type that is a mapping between a set of keys and a set of values. It represents a key-value pair enclosed in curly brackets and each element is separated by a comma. Key-value pairs are separated by the colon. The elements of the dictionaries are unordered and the key is unique for each value in the dictionary. The elements of the dictionary are mutable that is its elements can be changed once it is created.

Syntax:- Dictionaryname={key:value}

Example

Dict1={“comp”: “computer” , “sci” : “science”}

Dict2={“123”:”computer”,456 : “maths”}

Accessing Elements of the Dictionary

The elements of the dictionary are accessed with the help of the keys. Each key serves as an index and maps the value in the dictionary.

Syntax:- dictionaryname[key]

>>> dict1={"comp": "computer" , "sci" : "science"}
>>> dict1["comp"]
'computer'
>>> dict1["sci"]
'science'

New elements are added in the dictionary with the help of a new key.

>>> dict1={"comp": "computer" , "sci" : "science"}
>>> dict1["comm"]="commerce"
>>> dict1
{'comp': 'computer', 'sci': 'science', 'comm': 'commerce'}

Built-in Functions in the Dictionary

1) items() – items() function returns a list of tuples of key-value pair of the dictionary.

Syntax:- dictionaryname.items()

>>> dict1={"comp": "computer" , "sci" : "science","comm":"commerce"}
>>> dict1.items()
dict_items([('comp', 'computer'), ('sci', 'science'), ('comm', 'commerce')])

2) keys() – This function returns the list of keys in the dictionary.

Syntax:- dictionaryname.keys()

>>> dict1={"comp": "computer" , "sci" : "science","comm":"commerce"}
>>> dict1.keys()
dict_keys(['comp', 'sci', 'comm'])

3) values() – It returns the list of values in the dictionary.

Syntax:- dictionaryname.values()

>>> dict1={"comp": "computer" , "sci" : "science","comm":"commerce"}
>>> dict1.values()
dict_values(['computer', 'science', 'commerce'])

4) len() – length function is used to count the total number of elements in the dictionary.

Syntax:- len(dictionaryname)

>>> dict1={"comp": "computer" , "sci" : "science","comm":"commerce"}
>>> len(dict1)
3

5) update() –it is used to append the key-value pair of the dictionary passed as the argument to the key-value pair of the given dictionary.

Syntax:- dictionary1.update(dictionary2)

>>> dict1={"comp": "computer" , "sci" : "science","comm":"commerce"}
>>> dict2={"acc":"accounts","bst":"business studies"}
>>> dict1.update(dict2)
>>> dict1
{'comp': 'computer', 'sci': 'science', 'comm': 'commerce', 'acc': 'accounts', 'bst': 'business studies'}

Sets (set)

The set data type in Python is an unordered collection of unique elements. It is used to store multiple items without any duplicates. Sets are created by enclosing comma-separated elements within curly braces { } or by using the set() constructor.

Example: Set creation and accessing elements

# Creating a set

my_set = {1, 2, 3, 4, 5}

# Accessing elements

for element in my_set:

    print(element)

# Checking membership

is_present = 3 in my_set

# Printing the results

print(my_set)

print(is_present)

Output:

1

2

3

4

5

{1, 2, 3, 4, 5}

True

Example 2: Set operations

# Set operations

set1 = {1, 2, 3, 4, 5}

set2 = {4, 5, 6, 7, 8}

# Union of sets

union = set1.union(set2)

# Intersection of sets

intersection = set1.intersection(set2)

# Difference of sets

difference = set1.difference(set2)

# Printing the results

print(union)

print(intersection)

print(difference)

Output:

Copy code

{1, 2, 3, 4, 5, 6, 7, 8}

{4, 5}

{1, 2, 3}

Tuples (tuple)

The tuple data type in Python is similar to a list but with one crucial difference: tuples are immutable. Once created, the elements in a tuple cannot be modified. Tuples are created by enclosing comma-separated values within parentheses ( ).

Example: Tuple creation and accessing elements

# Creating a tuple

my_tuple = (1, 2, 3, 4, 5)

# Accessing elements by index

first_element = my_tuple[0]

last_element = my_tuple[-1]

# Slicing a tuple

subset = my_tuple[1:4]

# Printing the results

print(my_tuple)

print(first_element)

print(last_element)

print(subset)

Output:

(1, 2, 3, 4, 5)

1

5

(2, 3, 4)

Custom Data Types in Classes

In Python, classes provide a way to define custom data types. Classes encapsulate data and methods, allowing for the creation of objects with specific attributes and behaviors.Classes serve as blueprints for creating objects. They define the structure and behavior of objects, including their attributes (data) and methods (functions). Objects are instances of classes, and each object has its own unique state and behavior.

Example: Creating a class and instantiating objects

# Defining a class

class Point:

    def __init__(self, x, y):

        self.x = x

        self.y = y

# Creating objects

point1 = Point(2, 3)

point2 = Point(5, 7)

# Accessing object attributes

print(point1.x, point1.y)

print(point2.x, point2.y)

Output:

2 3

5 7

Example 2: Adding methods to a class

# Defining a class with methods

class Circle:

    def __init__(self, radius):

        self.radius = radius

    def area(self):

        return 3.14 * self.radius ** 2

# Creating an object and using methods

circle = Circle(5)

print(circle.area())

Output:

78.5

Conclusion

Python data types form the foundation of any Python programming endeavor. Understanding and utilizing these data types effectively is essential for developing robust and efficient applications. By mastering the intricacies of Python data types, you will have the necessary skills to tackle complex programming challenges.

If you still have doubts and need help with Python concepts, enroll in our Introduction to Python Program.

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Nishtha Arora 22 Jun 2023