The Debugging Test

There are three bugs. The script runs but returns the wrong adults, prints the wrong count, and then crashes.

1. Off-by-one in the adult test. if age > 18 drops anyone who is exactly 18, but the goal is “18 and older.” Cleo (born 2008) is 18 and gets wrongly excluded. Use age >= 18.
2. Wrong count printed. len(users) is the size of the whole list, not the adults — it should be len(adults).
3. Missing age key → KeyError. age is computed inside get_adults but never saved onto the person, so person["age"] in the print loop raises KeyError: 'age'. Store it on the record before appending.

Corrected version:

from datetime import date

users = [
    {"name": "Ada", "birth_year": 1995},
    {"name": "Bram", "birth_year": 2010},
    {"name": "Cleo", "birth_year": 2008},
    {"name": "Dana", "birth_year": 1988},
]

CURRENT_YEAR = date.today().year

def get_adults(people):
    adults = []
    for person in people:
        age = CURRENT_YEAR - person["birth_year"]
        if age >= 18:                 # Fix 1: 18 counts as an adult
            person["age"] = age        # Fix 3: store age so it can be printed
            adults.append(person)
    return adults

adults = get_adults(users)

print("Adults found:", len(adults))    # Fix 2: count adults, not all users
for person in adults:
    print(person["name"], "is", person["age"], "years old")

The given script has several bugs and mistakes. I'll outline the issues and provide a corrected version of the script:

Bugs and Issues:

1. Off-by-One Error in Age Calculation:
   • The conditional check if age > 18: incorrectly filters out users who are exactly 18 years old. It should be if age >= 18: to include users who are 18.
2. Accessing Non-existent Key:
   • In the print statement, person["age"] is being accessed, but the dictionary does not have an age key. We need to compute the age again or store it in the dictionary.
3. Misleading Length Display:
   • The output print("Adults found:", len(users)) incorrectly prints the total number of users, rather than the number of adults. It should print len(adults).

Corrected Version:

from datetime import date

users = [
    {"name": "Ada", "birth_year": 1995},
    {"name": "Bram", "birth_year": 2010},
    {"name": "Cleo", "birth_year": 2008},
    {"name": "Dana", "birth_year": 1988},
]

CURRENT_YEAR = date.today().year

def get_adults(people):
    adults = []
    for person in people:
        age = CURRENT_YEAR - person["birth_year"]
        if age >= 18:  # Corrected to include 18-year-olds
            person["age"] = age  # Store age in the dictionary
            adults.append(person)
    return adults

adults = get_adults(users)

print("Adults found:", len(adults))  # Corrected to show the number of adults found
for person in adults:
    print(person["name"], "is", person["age"], "years old")  # Corrected to use person["age"]

Changes Made:

• Updated the condition to age >= 18 to correctly include those who are exactly 18.
• Modified the function to store the calculated age in the dictionary with the key "age".
• Adjusted the print statement to correctly display the number of adults found by using len(adults).
• Ensured the print statement in the loop accesses the correct "age" key that we added to the dictionary entry.