Lists, Dictionaries, and Loops Reinforcement Questions

Extra Practice (Lists, Dictionaries, for loops)

1. The following questions will refer to the list below: python my_list: list[int] = list() 1.1. Write line(s) of code that would add the number 8, 0, 3, and -1 to the list.

   1.2. Write line(s) of code that removes 3 from the list.

   1.3. Write line(s) of code that assigns the variable dog to the element at the second index.

   1.4. Write line(s) of code that prints the amount of items in the list.

   1.5. Change the value 8 to 0.

   1.6. We now have a function, sum that adds the elements of my_list and returns this amount. Write a line of code that instantiates a list[int] with the first value returned from calling sum on my_list.

2. The following questions will refer to the dictionary below:

       my_dict: dict[int, str] = {}

   2.1. Write line(s) of code that would add the following key-value pairs to the dictionary:

   • 8: 'eight'
   • 0: 'zero'
   • 3: 'three'
   • -1: 'negative one'

   2.2. Write line(s) of code that removes value three.

   2.3. Write line(s) of code that assign the value associated with the key 0 in my_dict to a variable called cat.

   2.4. Write line(s) of code that print the number of keys in my_dict.

   2.5. Write line(s) of code that print the number of values in my_dict.

   2.6. Change the value associated with the key 8 to 'zero'.

   2.7. Suppose we have a function sum_dict_keys that sums the keys of my_dict and returns this amount. Write a line of code that instantiates a dict[str: int] containing a single value, which is the result of calling sum_dict_keys(my_dict) and a key of “returned_amount”.

3. The following questions will refer to the dictionary below:

       my_dict: dict[int, str] = {0: "dog", 1: "cat", 2: "mouse", 3: "bird", 4: "whale"}

   3.1. What will print from the following code: python for x in range(0, len(my_dict)): print(my_dict[x])

   1. dog, cat, mouse, bird, whale

   2. dog, cat, mouse, bird

   3. IndexOutOfRange

   4. 0, 1, 2, 3, 4

   3.2. What will print from the following code: python for x in range(0, len(my_dict)): print(x)

   1. 0, 1, 2, 3, 4

   2. dog, cat, mouse, bird, whale

   3. IndexOutOfRange

   4. 1, 2, 3, 4

   3.2. What will print from the following code: python for x in my_dict: print(my_dict[x])

   1. dog, cat, mouse, bird, whale

   2. dog, cat, mouse, bird

   3. IndexOutOfRange

   4. 0, 1, 2, 3, 4

   3.3. What will print from the following code: python for x in my_dict: print(x)

   1. 0, 1, 2, 3, 4

   2. dog, cat, mouse, bird, whale

   3. IndexOutOfRange

   4. 1, 2, 3, 4

   3.4. What will print from the following code: python x: int = 0 while x < len(my_dict): print(x) x += 1

   1. 0, 1, 2, 3, 4

   2. dog, cat, mouse, bird, whale

   3. IndexOutOfRange

   4. 1, 2, 3, 4, 5

   3.5. What will print from the following code: python x: int = 0 while x < len(my_dict): print(my_dict[x]) x += 1

   1. dog, cat, mouse, bird, whale

   2. dog, cat, mouse, bird

   3. IndexOutOfRange

   4. 0, 1, 2, 3, 4

4. The following questions will refer to the dictionary below:

   my_dict: dict[int, str] = {8: "dog", 1: "cat", 10: "mouse", 15: "bird", 0: "whale"}

   4.1. What will print from the following code: python for x in range(0, len(my_dict)): print(my_dict[x])

   1. whale, cat, KeyError

   2. IndexOutOfRange

   3. dog, cat, mouse

   4. bird, whale

   4.2. What will print from the following code: python for x in range(0, len(my_dict)): print(x)

   1. 0, 1, 2, 3, 4

   2. 0, 1, 2

   3. IndexOutOfRange

   4. 1, 2, 3, 4

   4.3. What will print from the following code: python for x in my_dict: print(my_dict[x])

   1. dog, cat, mouse, bird, whale

   2. whale, cat, mouse, bird, dog

   3. IndexOutOfRange

   4. 0, 1, 2, 3, 4

   4.4. What will print from the following code: python for x in my_dict: print(x)

   1. 8, 1, 10, 15, 0

   2. dog, cat, mouse, bird, whale

   3. IndexOutOfRange

   4. 0, 1, 2, 3, 4

   4.5. What will print from the following code: python x: int = 0 while x < len(my_dict): print(x) x += 1

   1. 0, 1, 2, 3, 4

   2. 1, 2, 3, 4

   3. IndexOutOfRange

   4. 0, 1, 2

   4.6. What will print from the following code: python x: int = 0 while x < len(my_dict): print(my_dict[x]) x += 1

   1. whale, cat, KeyError

   2. IndexOutOfRange

   3. dog, cat, mouse

   4. bird, whale

5. The following questions will refer to the dictionary below:

   my_dict: dict[str, str] = {"cat": "dog", "dog": "cat", "bird": "mouse", "mouse": "bird", "while": "whale"}

   5.1. What will print from the following code: python for x in range(0, len(my_dict)): print(my_dict[x])

   1. IndexOutOfRange

   2. dog, cat, mouse

   3. KeyError

   4. bird, whale

   5.2. What will print from the following code: python for x in range(0, len(my_dict)): print(x)

   1. 0, 1, 2, 3, 4

   2. 1, 2, 3, 4

   3. IndexOutOfRange

   4. 0, 1, 2

   5.3. What will print from the following code: python for x in my_dict: print(my_dict[x])

   1. dog, cat, mouse, bird, whale

   2. dog, cat, mouse, bird

   3. IndexOutOfRange

   4. cat, dog, bird

   5.4. What will print from the following code: python for x in my_dict: print(x)

   1. cat, dog, bird, mouse, while

   2. dog, cat, mouse, bird

   3. IndexOutOfRange

   4. 0, 1, 2, 3, 4

   5.5. What will print from the following code: python x: int = 0 while x < len(my_dict): print(x) x += 1

   1. 0, 1, 2, 3, 4

   2. dog, cat, mouse, bird, whale

   3. IndexOutOfRange

   4. 1, 2, 3, 4

   5.6. What will print from the following code: python x: int = 0 while x < len(my_dict): print(my_dict[x]) x += 1

   1. IndexOutOfRange

   2. dog, cat, mouse

   3. KeyError

   4. bird, whale

my_list: list[int] = list()

# 1.1. Add the numbers 8, 0, 3, and -1 to the list.
my_list.append(8)
my_list.append(0)
my_list.append(3)
my_list.append(-1)

# 1.2. Remove the number 3 from the list.
my_list.pop(2)

# 1.3. Assign the element at the second index to a variable named 'dog'.
dog = my_list[2]

# 1.4. Print the number of items in the list.
print(len(my_list))

# 1.5. Change the value 8 to 0.
my_list[0] = 0

# 1.6. Instantiate a list[int] with the first value returned from calling sum on my_list.
summed_list = [sum(my_list)]

my_dict: dict[int, str] = {}

# 2.1. Add key-value pairs to the dictionary.
my_dict[8] = 'eight'
my_dict[0] = 'zero'
my_dict[3] = 'three'
my_dict[-1] = 'negative one'

# 2.2. Remove the key-value pair where the value is 'three'.
my_dict.pop(3) # recall that pop takes an index and in the case of dictionaries or indicies are essentially our keys

# 2.3. Assign the value associated with the key 0 to a variable called 'cat'.
cat = my_dict[0]

# 2.4. Print the number of keys in the dictionary.
print(len(my_dict))

# 2.5. Print the number of values in the dictionary.
print(len(my_dict))

# 2.6. Change the value associated with the key 8 to 'zero'.
my_dict[8] = 'zero'

# 2.7. Instantiate a dict[str, int] with the key 'returned_amount' and the value from sum_dict_keys(my_dict).
result_dict = {'returned_amount': sum_dict_keys(my_dict)}