Section 3D: Collect and process data using dictionaries

Which of the following is the correct way to create an empty dictionary in Python?

• `my_dict = []`

• `my_dict = {}`

• `my_dict = ()`

• `my_dict = set()`

What will be the output of the following code? ```python my_dict = {'a': 1, 'b': 2} print(my_dict['b']) ```

• `'b'`

• `1`

• `2`

• `KeyError`

Which method would you use to get a list of all the keys in a dictionary?

• `values()`

• `items()`

• `keys()`

• `get()`

How do you add a new key-value pair to an existing dictionary called `d` with key `'x'` and value `10`?

• `d.add('x', 10)`

• `d['x'] = 10`

• `d.append('x', 10)`

• `d.insert('x', 10)`

Which of the following statements will remove the key `'age'` from the dictionary `person`?

• `person.remove('age')`

• `del person['age']`

• `person.popitem('age')`

• `person.clear('age')`

Given the dictionary `d = {'a': 1, 'b': 2, 'c': 3}`, which code will check if the key `'b'` exists in `d`?

• `'b' in d`

• `d.has_key('b')`

• `'b' == d`

• `d['b'] == None`

Which method returns a view object that displays a list of a dictionary's key-value tuple pairs?

• `keys()`

• `values()`

• `items()`

• `pairs()`

Suppose you have the dictionary `d = {'x': 5, 'y': 10}`. Which code will print all the values in the dictionary?

• `print(d.keys())`

• `print(d.items())`

• `print(d.values())`

• `print(d.all())`

Given `d = {'a': 1, 'b': 2, 'c': 3}`, which code will iterate through all the keys and print them?

• `for key in d: print(key)`

• `for key in d.keys(): print(key)`

• Both A and B

• `for key in d.values(): print(key)`

If you want to remove a key-value pair from a dictionary and get its value at the same time, which method should you use?

• `remove()`

• `pop()`

• `del`

• `clear()`