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Variables and Assignment in Python
What is a Variable?
- A variable is a name that refers to a value stored in memory.
- It acts as a reference, not a storage container.
- Unlike other languages, Python variables do not store values but rather point to objects in memory.
- Example:
x = 10 # x refers to an object holding the value 10Variables Are Not Storage Containers
- In Python, variables are like labels attached to objects in memory.
- Assigning a variable does not copy data; it creates a reference.
- Example:
a = [1, 2, 3] # a points to a list objectb = a # b refers to the same list, not a copy- Changing
baffectsabecause both reference the same object.
b.append(4) # Modifies the listprint(a) # Output: [1, 2, 3, 4]Variable Assignment in Python
- The assignment operator (
=) is used to bind variables to values. - Python allows multiple assignments in a single statement.
- Example:
a, b, c = 5, 10, 15name = "Alice"Multiple Assignment in Python
- Python allows assigning multiple values to multiple variables in one line.
- This feature makes code more concise and readable.
x, y, z = 1, 2, 3 # Assigning different valuesa = b = c = 100 # Assigning the same value to multiple variables- Swapping values using multiple assignment:
a, b = b, a # Swap values of a and bDynamic Typing in Python
- Python is dynamically typed.
- The type of a variable is determined at runtime.
- You can reassign a variable to a different type.
x = 5 # Integerx = "Hello" # Now a stringBest Practices for Variable Naming
- Use meaningful variable names.
- Follow the PEP 8 naming conventions.
- Avoid using Python keywords as variable names.
- Example of valid names:
student_name = "John"total_marks = 95Video
Summary
- Variables in Python are references, not storage containers.
- The assignment operator
=creates a reference. - Python supports multiple assignments.
- Python supports dynamic typing.
- Follow best practices for variable naming.
Thank You!