Session 3

Assignment

Complete should_serve_customer. Return True only if: customer_age >= 21, bartender is not on break, time is between 5 and 10 inclusive. The tips suggest inverting the logic — return False early for each failing condition.

Solution

def should_serve_customer(customer_age, on_break, time):
    if customer_age < 21:
        return False
    elif on_break:
        return False
    elif time < 5 or time > 10:
        return False
    else:
        return True

Concept

Inverted logic (returning False early), elif, or operator, boolean simplification, not operator

How it went

Grasped inverted logic well. Initially wrote time < 5 > 10 instead of time < 5 or time > 10 — read it out loud, identified fix himself. Applied on_break simplification unprompted. Passed all 9 test cases.

Ratings

Key takeaways

• →Chained comparisons like `time < 5 > 10` don't work — write explicitly: `time < 5 or time > 10`
• →Simplify booleans: `on_break` not `on_break == True`, `not has_id` not `has_id == 0`

Assignment

Complete check_mount_rental. If time_used >= time_purchased return 'overtime charged'. Otherwise return 'no charges yet'. Bonus: try without an else statement.

Solution

def check_mount_rental(time_used, time_purchased):
    if time_used >= time_purchased:
        return "overtime charged"
    return "no charges yet"

Concept

>= comparison, returning strings based on condition, indentation as structure, fallback return without else

How it went

Got comparison operator right first time. Had both return statements inside if block initially. Once explained using parent/child framing — 'the if is the child, the function is the parent' — understood immediately and fixed it. Final solution has no else.

Ratings

Key takeaways

• →Indentation is structure, not style. Ask: what lines should only run if this condition is true? Those get indented. Everything else stays at the parent level

Assignment

Complete combat_evaluation. Set advantage=True if player_power > enemy_defense, evenly_matched=True if equal, otherwise disadvantage=True. Set the remaining variables to False.

Solution

def combat_evaluation(player_power, enemy_defense):
    advantage, disadvantage, evenly_matched = False, False, False

    if player_power > enemy_defense:
        advantage = True
    elif player_power == enemy_defense:
        evenly_matched = True
    else:
        disadvantage = True

    return advantage, disadvantage, evenly_matched

Concept

if/elif/else blocks, > and ==, setting variables inside conditionals, returning multiple values

How it went

Completed after struggling — the right outcome. Indentation clicked with parent/child framing. Initially wrote age > 18 instead of >= 18 and had string case error — both self-corrected after leading questions. Applied on_break simplification unprompted.

Ratings

Key takeaways

• →Watch > vs >= — at boundary values they produce different results. Double-check threshold conditions