Knowledge Check: Module 21

Test your knowledge! Answer 10 questions. You need at least 6 correct answers to pass (). You can retake the quiz as many times as needed. Good luck!

1Which method is commonly used to iterate over only the keys of a dictionary called `my_dict`?

for item in my_dict.items(): for key in my_dict: for value in my_dict.values(): for index in range(len(my_dict)):

2How can you get a list of all values from a dictionary `student_grades`?

list(student_grades.keys()) student_grades.get_values() list(student_grades.values()) student_grades[:]

3What does the `items()` method return when called on a dictionary?

A list of keys. A list of values. A view object containing key-value tuple pairs. The dictionary itself.

4How do you check if a key named `'city'` exists in a dictionary `user_profile`?

'city' in user_profile user_profile.has_key('city') (Note: Outdated in Python 3) user_profile.exists('city') user_profile['city'] != None

5What is the primary purpose of the `del` keyword when used with a dictionary item like `del data['temp']`?

To retrieve the value associated with the key `'temp'`. To check if the key `'temp'` exists. To remove the key-value pair associated with the key `'temp'` from the dictionary. To set the value of `'temp'` to `None`.

6Consider `inventory = {'apples': 10, 'bananas': 5}`. What happens if you execute `removed_item = inventory.pop('oranges', 0)`?

It raises a `KeyError` because `'oranges'` is not in the dictionary. `removed_item` becomes `0`, and the dictionary remains unchanged. `removed_item` becomes `None`, and the dictionary remains unchanged. It adds `'oranges': 0` to the dictionary.

7Which method allows you to get a value for a key but returns a default value (e.g., `None` or a specified value) if the key is not found, without raising an error?

my_dict[key] my_dict.find(key, default) my_dict.fetch(key, default) my_dict.get(key, default)

8If you iterate through a dictionary using `for k, v in my_dict.items():`, what do `k` and `v` represent in each iteration?

`k` is the index, `v` is the key. `k` is the key, `v` is the value. `k` is the value, `v` is the key. `k` is the key, `v` is the index.

9What is the result of `len({'name': 'Alice', 'age': 30, 'city': 'New York'})`?

2 3 6 It raises a `TypeError`.

10Which of the following correctly creates an empty dictionary?

my_dict = [] my_dict = () my_dict = {} or my_dict = dict() my_dict = new Dictionary()