Python: Using Dictionaries

Question 1

Once you have a dictionary, you can access the values in it by providing the __?__

Answer 1

key

Question 2

what is the syntax to access the values of a dictionary?

Answer 2

dictionary[“key”]

Question 3

how would you check to determine if a key exists in a dictionary?
key = “Landmark 81”
dictionary = building_heights

Answer 3

key_to_check = “Landmark 81”

if key_to_check in building_heights:

print(building_heights[“Landmark 81”])

Question 4

update the line of code below to include the try/except method

key_to_check = “Landmark 81”

print(building_heights[key_to_check])
except KeyError:
print(“That key doesn’t exist!”)

Answer 4

key_to_check = "Landmark 81"
try:
  print(building_heights[key_to_check])
except KeyError:
  print("That key doesn't exist!")

Question 5

what method can be used to search for a value in a dictionary besides my_dict[key] notation?

Answer 5

the .get() method

Question 6

what syntax do we use to remove a key from a dictionary ?

Answer 6

.pop()

Question 7

__?__ works to delete items from a dictionary, when you know the key value.

Answer 7

.pop()

Question 8

From the list below:
In one line, add the value of “stamina grains” to health_points and remove the item from the dictionary. If the key does not exist, add 0 to health_points.

available_items = {"health potion": 10, "cake of the cure": 5, "green elixir": 20, "strength sandwich": 25, "stamina grains": 15, "power stew": 30}
health_points = 20

Answer 8

health_points += available_items.pop(“stamina grains”, 0)

Question 9

Using the dictionary below.

test_scores = {“Grace”:[80, 72, 90], “Jeffrey”:[88, 68, 81], “Sylvia”:[80, 82, 84], “Pedro”:[98, 96, 95], “Martin”:[78, 80, 78], “Dina”:[64, 60, 75]}

write a code to print print out the list of keys in the dictionary.

Answer 9

for student in test_scores.keys():

print(student)

Question 10

Create a variable called users and assign it to be all of the keys of the user_ids list.

Answer 10

users = user_ids.keys()

Question 11

Create a variable called total_exercises and set it equal to 0.

Iterate through the values in the num_exercises list and add each value to the total_exercises variable.

Answer 11

total_exercises = 0

for exercises in num_exercises.values():
total_exercises += exercises