# ============================================================ # Arithmetic operators # ============================================================ print(7 / 3) # 2.3333... (true division — always returns float) print(7 // 3) # 2 (floor division — rounds toward negative infinity) print(-7 // 3) # -3 (NOT -2! Rounds toward negative infinity) print(7 % 3) # 1 (modulus) print(-7 % 3) # 2 (Python's modulus always returns non-negative for positive divisor) # Exponentiation print(2 ** 10) # 1024 print(16 ** 0.5) # 4.0 (square root) print(pow(2, 10)) # 1024 (built-in function) print(pow(2, 10, 1000)) # 24 (modular exponentiation: 2^10 % 1000) # ============================================================ # Comparison chaining (Pythonic!) # ============================================================ age = 25 # BAD (other languages style): if age >= 18 and age <= 65: print("Working age") # GOOD (Pythonic): if 18 <= age <= 65: print("Working age") # Multiple chaining x = 5 print(1 < x < 10) # True print(1 < x < 10 < 100) # True (all comparisons must be true) # ============================================================ # Logical operators: and, or, not # ============================================================ # 'and' returns first falsy value, or last value if all truthy print(1 and 2 and 3) # 3 (all truthy, returns last) print(1 and 0 and 3) # 0 (first falsy value) print(1 and "" and 3) # "" (first falsy value) # 'or' returns first truthy value, or last value if all falsy print(0 or "" or 3) # 3 (first truthy value) print(0 or "" or []) # [] (all falsy, returns last) # Practical use: default values name = "" display_name = name or "Anonymous" # "Anonymous" print(display_name) # Short-circuit evaluation # 'and' stops at first falsy — right side not evaluated x = 0 result = x != 0 and 10 / x # 10/x never executes (no ZeroDivisionError) print(result) # False # ============================================================ # Walrus operator := (Python 3.8+) # ============================================================ # Without walrus — compute twice or use temp variable data = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] # BAD: compute len() twice # if len(data) > 5: # print(f"List has {len(data)} items") # GOOD: compute once with walrus if (n := len(data)) > 5: print(f"List has {n} items") # In while loops — read and check in one line import io buffer = io.StringIO("line1\nline2\nline3\n") while (line := buffer.readline()): print(f"Read: {line.strip()}") # In list comprehensions — filter and transform numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] results = [y for x in numbers if (y := x ** 2) > 20] print(results) # [25, 36, 49, 64, 81, 100] # ============================================================ # Membership and identity operators # ============================================================ fruits = ["apple", "banana", "cherry"] print("banana" in fruits) # True print("grape" not in fruits) # True # 'in' works with strings too print("hell" in "hello world") # True # 'in' with dictionaries checks keys (not values) user = {"name": "Alice", "age": 30} print("name" in user) # True (checks keys) print("Alice" in user) # False (not a key) # Identity checks a = [1, 2, 3] b = [1, 2, 3] print(a == b) # True (same value) print(a is b) # False (different objects) c = a print(a is c) # True (same object) # ============================================================ # Bitwise operators # ============================================================ a, b = 0b1010, 0b1100 # 10, 12 print(f"a & b = {a & b:04b}") # 1000 (AND) print(f"a | b = {a | b:04b}") # 1110 (OR) print(f"a ^ b = {a ^ b:04b}") # 0110 (XOR) print(f"~a = {~a}") # -11 (NOT — two's complement) print(f"a << 2 = {a << 2}") # 40 (left shift) print(f"a >> 1 = {a >> 1}") # 5 (right shift) # Practical: using sets with bitwise operators set_a = {1, 2, 3, 4} set_b = {3, 4, 5, 6} print(set_a & set_b) # {3, 4} — intersection print(set_a | set_b) # {1, 2, 3, 4, 5, 6} — union print(set_a ^ set_b) # {1, 2, 5, 6} — symmetric difference print(set_a - set_b) # {1, 2} — difference

Phase 1: Python Fundamentals & Setup

0 of 4 topics completed

Python Ecosystem & Philosophy

Installation & Environment Setup

Variables & Data Types

Operators & Expressions

🎤 Mock Interview