Data Types in Python: Strings, Numbers, and Lists

In Python, data types define the nature of the values that can be stored and manipulated in a program. Understanding key data types like strings, numbers, and lists is fundamental to working with Python effectively.

1. Strings:

Definition: A string is a sequence of characters, and it is used to represent text in Python. Strings are enclosed in single (') or double (") quotes.

Example:

message = "Hello, Python!"

Operations:

• Concatenation: Combining strings using the + operator.

greeting = "Hello, " name = "Python" full_message = greeting + name

• Length: Finding the length of a string using the len() function.

message = "Hello, Python!" length = len(message)

• Indexing and Slicing: Accessing individual characters or portions of a string.

message = "Hello, Python!" first_char = message[0] substring = message[7:13] # Extracts "Python"

2. Numbers:

Definition: Numbers in Python include integers (whole numbers) and floats (decimal numbers).

Examples:

integer_number = 42 float_number = 3.14

Operations:

• Arithmetic: Performing basic arithmetic operations such as addition, subtraction, multiplication, and division.

result = 10 + 5 # Addition result = 20 - 8 # Subtraction result = 5 * 3 # Multiplication result = 15 / 4 # Division (returns a float)

• Modulo: Getting the remainder of a division using the % operator.

remainder = 15 % 4

3. Lists:

Definition: A list is an ordered collection of items. It can contain elements of different data types, and the elements can be modified.

Example:

fruits = ["apple", "orange", "banana"]

Operations:

• Accessing Elements: Retrieving elements from a list using indexing.

first_fruit = fruits[0]

• Slicing: Extracting a portion of a list.

selected_fruits = fruits[1:3] # Returns ["orange", "banana"]

• Modifying Elements: Changing the value of an element in the list.

fruits[0] = "kiwi"

• Adding Elements: Appending or inserting new elements into a list.

fruits.append("grape") fruits.insert(1, "pear")

These fundamental data types—strings, numbers, and lists—serve as the building blocks for more complex data structures and operations in Python. By mastering their use, you can effectively handle a wide range of data and perform various tasks in your Python programs.