Python Variables

In Python, a variable is a named storage location that holds a value. Unlike some other programming languages, you don’t need to declare the type of a variable explicitly in Python; the interpreter dynamically determines the type based on the value assigned to it. Here’s how you work with variables in Python:

Variable Naming Rules:

Variable names can contain letters (a-z, A-Z), numbers (0-9), and underscores (_).
Variable names cannot start with a number.
Python keywords (reserved words like if, else, for, etc.) cannot be used as variable names.
Variable names are case-sensitive (‘age’ and ‘Age’ are treated as different variables).

Assigning Values to Variables:

				
					# Variable assignment
age = 25
name = "John"
is_student = True

In the example above, we’ve assigned values to three variables: ‘age‘, ‘name‘, and ‘is_student‘. Python infers the data type of each variable based on the assigned values

Variable Types:

Integer:

				
					age = 25

Float:

				
					height = 5.9

String:

				
					name = "John"

Boolean:

				
					is_student = True

Reassigning Variables:

				
					x = 10
print(x)  # Outputs: 10

x = "Hello"
print(x)  # Outputs: Hello

In Python, you can reassign a variable to a different type without any explicit type declaration.

Dynamic Typing:

				
					variable = 42  # integer
print(variable)

variable = "Hello, World!"  # string
print(variable)

Python is dynamically typed, meaning you can change the type of a variable on-the-fly.

Concatenating Strings:

				
					first_name = "John"
last_name = "Doe"
full_name = first_name + " " + last_name
print(full_name)  # Outputs: John Doe

Strings can be concatenated using the + operator.

Best Practices:

Choose meaningful variable names to enhance code readability.
Use lowercase letters with underscores for variable names (e.g., user_age).
Be consistent in your naming conventions throughout your code.

Understanding how to work with variables is fundamental to programming in Python. They allow you to store and manipulate data, making your programs flexible and dynamic.