Python Operators

Operators are the symbols that drive the logic of any programming language. They act as the engine for calculations, data manipulation, and decision-making.

1. Arithmetic Operators – Math

These operators perform standard mathematical calculations.

The Power of Modulus %

The modulus operator is essential for logic, not just math.

• Even/Odd Check: If number % 2 == 0, the number is Even.
• Cyclic Indexing: If you want to loop through a list of 5 items continuously, use index % 5. The result cycles through 0, 1, 2, 3, 4, then resets to 0 automatically.

2. Assignment Operators

Used to assign and update values in variables.

The Walrus Operator :=

A special operator that allows you to assign a value to a variable inside an expression (like an if statement).

# Instead of 2 lines:
# n = len(text)
# if n > 10: ...

# Do it in 1 line:
if (n := len(text)) > 10:
    print(f"Too long: {n} chars")

3. Comparison Operators

Used to compare two values. They always return a Boolean (True or False).

Chained Comparisons

Python allows math-like chaining, which is cleaner than using multiple and statements.

x = 10
# Clean Pythonic way
if 5 < x < 20:
    print("x is between 5 and 20")

4. Logical Operators

Used to combine conditional statements. These follow Boolean logic.

Short-Circuit Evaluation

Python evaluates logic lazily to save resources.

• and Short-Circuit: If the first condition is False, Python stops immediately (result is definitely False).
• or Short-Circuit: If the first condition is True, Python stops immediately (result is definitely True).

Real World Use: Preventing crashes.

# Safe Code
# Python checks 'len > 0' first. If False, it never runs index[0], preventing a crash.
if len(my_list) > 0 and my_list[0] == "Admin":
    print("Welcome Admin")

5. Identity Operators is

Used to compare Objects (Memory), not just Values (Data).

The Trap: is vs ==

• == checks Content: “Do these variables hold the same data?”
• is checks Address: “Do these variables point to the exact same memory slot?”

list1 = [1, 2, 3]
list2 = [1, 2, 3] # A copy

print(list1 == list2) # True (Data is same)
print(list1 is list2) # False (They are two different lists in memory)

6. Membership Operators in

Used to test if a sequence (List, String, Tuple, Dict) contains a specific value.

7. Bitwise Operators

Used to manipulate data at the binary level (bits). Critical for permissions, encryption, and low-level optimization.

8. Operator Precedence

When multiple operators appear in one line, Python follows a strict hierarchy.

9. Operator Overloading – Magic Methods

You can change how operators behave for your own custom classes. For example, if you create a Wallet class, you can teach Python how to add two wallets together using +.

You define special methods (Double Underscore or “Dunder” methods):

• __add__ handles +
• __sub__ handles –
• __eq__ handles ==

class Wallet:
    def __init__(self, money):
        self.money = money

    # Teach Python what to do when we use '+' on Wallets
    def __add__(self, other):
        return Wallet(self.money + other.money)

w1 = Wallet(50)
w2 = Wallet(100)
w3 = w1 + w2  # Python calls w1.__add__(w2)

print(w3.money) # Output: 150