"""

03_operators.py

Purpose: arithmetic, comparison, logical, assignment, membership, identity.

"""

def header(t): print("\n***", t, "***\n")

header("Arithmetic")

a, b = 9, 4

print("a + b =", a + b)

print("a - b =", a - b)

print("a * b =", a * b)

print("a / b =", a / b) # float division

print("a // b =", a // b) # floor division

print("a % b =", a % b) # remainder

print("a ** b =", a ** b) # power

header("Comparison")

print(a > b, a < b, a == b, a != b)

header("Logical operators and truthiness")

print(True and False, True or False, not True)

print("Truthiness examples:", bool([]), bool([1]), bool(""), bool("hi"))

header("Assignment and augmented assignment")

c = 5

c += 2 # c = c + 2

print("c after +=2:", c)

header("Membership and identity")

lst = [1,2,3]

print("2 in lst?", 2 in lst)

x = [1,2]

y = x

z = [1,2]

print("x is y?", x is y) # same object

print("x is z?", x is z) # equal but different object

print("x == z?", x == z) # equality checks values

header("Operator precedence")

# parentheses first, then **, then unary +/-, then *,/,//,%, then +,-

print("Precedence example:", 2 + 3 * 4) # -> 14

print("With parentheses:", (2 + 3) * 4) # -> 20

header("Mini Exercises")

# 1) Compute BMI = weight_kg / (height_m ** 2) and print classification using comparisons.

# 2) Predict the output of: True + True, True * 5