基于/2+7规则的Python年龄判断程序逻辑错误排查求助

Hey there! Let's work through your Python age-checker problem step by step—you're already on the right track, just a couple of logic kinks to iron out.

First, let's fix the initial code's core mistake #

Your original first condition if num1 and num2 <= 17: was a classic Python logic slip-up. In Python, and needs two full boolean expressions to work correctly. Here, num1 gets treated as a boolean (any non-zero number counts as True), so this line was actually checking "is num1 not zero AND is num2 <=17"—not "are both ages <=17". You fixed this correctly in your revised code by changing it to if num1 <= 17 and num2 <= 17:—great call.

The new problem: Condition order is messing up your results #

Your revised code has a logic ordering issue that's causing unexpected outputs:

• When you test num1=19, num2=16, the code hits the elif num2 <=17 condition first and prints "You're going to jail bud", but you expect it to print the "slightly too young" message. This happens because you're checking for underage status before verifying the age rule.
• When both ages are over 17, the code hitting the else clause is actually normal for cases where the lower age is below the num1/2 +7 threshold (e.g., num1=25, num2=18 gives a minimum acceptable age of 19.5, so 18 is too young).

Fixed code with logical ordering and input safety #

Let's reorder the conditions to prioritize the age rule first, add a check to make sure the user didn't mix up higher/lower ages, and use clearer variable names:

num1 = float(input("What is the higher age number? "))
num2 = float(input("What is the lower age number? "))

# Quick check to fix swapped ages (easy mistake to make!)
if num1 < num2:
    print("Oops, you swapped the ages! Let me fix that for you.")
    num1, num2 = num2, num1

min_acceptable_age = num1 / 2 + 7

# 1. First, check if both are underage
if num1 <= 17 and num2 <= 17:
    print("You're both underage")
# 2. Next, check if the lower age meets the 1/2 +7 rule
elif num2 >= min_acceptable_age:
    print("That's OK")
# 3. Then, check if only the lower age is underage (and failed the rule)
elif num2 <= 17:
    print("You're going to jail bud")
# 4. Finally, handle cases where both are adult but lower age is too young
else:
    print("They are slightly too young for you")

Let's test this with your edge cases #

• num1=19, num2=16: The minimum acceptable age is 16.5. Since 16 < 16.5 and 16 is under 18, it prints "You're going to jail bud" (if you really want this to print "slightly too young" instead, you'd need to adjust the underage threshold, but this aligns with standard logic around minor-adult relationships).
• num1=88, num2=77: Minimum acceptable age is 51, so 77 >=51 → prints "That's OK".
• num1=19, num2=19: Minimum acceptable age is 16.5, 19 >=16.5 → prints "That's OK".
• num1=25, num2=18: Minimum acceptable age is 19.5, 18 <19.5 and 18 is adult → prints "They are slightly too young for you".

内容的提问来源于stack exchange，提问作者Brandon