Methods and Functions

Question 1

return a random integer between min and max inclusive

Answer 1

randint(min, max)

Question 2

return a random integer between min and max-1 inclusive

Answer 2

randrange(min, max)

Question 3

add a value to the end of a list

Answer 3

my_list.append(value)

Question 4

remove the element at the index i from a list

Answer 4

my_list.pop(i)

Question 5

remove the first element whose value matches

Answer 5

my_list.remove(‘abc’)

Question 6

get the length of a list # of items in the list or in a set

Answer 6

len(list) len(set)

Question 7

produce a new list by adding two lists together, order of definition is order in list

Answer 7

list1 + list2

Question 8

find the element in the list with the smallest value

Answer 8

min(list)

Question 9

find the element in the list with the largest value

Answer 9

max(list)

Question 10

find the sum of all list elements (numbers only)

Answer 10

sum(list)

Question 11

find the index of the first matching value in the list

Answer 11

list.index(value)

Question 12

count the number of occurrences in a list

Answer 12

list.count(value)

Question 13

add elements from one set to another set
add elements from one dictionary to another dictionary

Answer 13

set1.update(set2)
my_dict1.update(my_dict2)

Question 14

add a value into the set

Answer 14

set.add(value)

Question 15

remove value from a set. raises KeyError if not found

Answer 15

set.remove(value)

Question 16

remove a random element from the set

Answer 16

set.pop()

Question 17

clear all elements from a set

Answer 17

set.clear()

Question 18

return a new set containing only the elements in common between set and provided sets

Answer 18

set.intersection(set_a, set_b, set_c)

Question 19

return a new set containing all of the unique elements in all sets

Answer 19

set.union(set_a, set_b, set_c)

Question 20

return a set containing only the elements of the set that are not found in any of the provided sets

Answer 20

set.difference(set_a, set_b, set_c)

Question 21

return a set containing only the elements that appear in exactly one of set_a or set_b

Answer 21

set_a.symmetric_difference(set_b)

Question 22

Adding new entries to a dictionary:

Answer 22

dict[k] = v: Adds the new key-value pair k-v, if dict[k] does not already exist.
Example: students[‘John’] = ‘A+’

Question 23

Modifying existing entries in a dictionary:

Answer 23

dict[k] = v: Updates the existing entry dict[k], if dict[k] already exists.
Example: students[‘Jessica’] = ‘A+’

Question 24

Removing entries from a dictionary:

Answer 24

del dict[k]: Deletes the entry dict[k].
Example: del students[‘Rachel’]

Question 25

Add all items in [x] to list.

Answer 25

my_list = [5, 8] my_list.extend([4, 12]) [5, 8, 4, 12] Extends the list by appending all items from an iterable.

Question 26

Insert x into list before position i.

Answer 26

my_list = [5, 8] my_list.insert(1, 1.7) [5, 1.7, 8]

Question 27

Sort the items of list in-place.

Answer 27

my_list = [14, 5, 8] my_list.sort() [5, 8, 14]

Question 28

Reverse the elements of list in-place.

Answer 28

my_list = [14, 5, 8] my_list.reverse() [8, 5, 14]

Question 29

Returns a new sorted list from the items in the original list.

Answer 29

sorted(list)

Question 30

Returns an iterator that accesses the elements of the list in reverse order.

Answer 30

reversed(list)

Question 31

work on a copy of a list

Answer 31

my_list[:]

Question 32

copy a dictionary

Answer 32

my_dict.copy()

Question 33

empty all values from a list or dictionary

Answer 33

my_list.clear() my_dict.clear()

Question 34

Returns a new dictionary with specified keys and a default value.

Answer 34

my_dict.fromkeys(keys, value)

Question 35

Returns the value for the specified dictionary key, or None if the key does not exist.

Answer 35

my_dict.get(key, 'optional default if none exists')

Question 36

Returns a view object of the dictionary’s key-value pairs.

Answer 36

my_dict.items() num_calories = dict(Coke=90, Coke_zero=0, Pepsi=94) for soda, calories in num_calories.items(): print(f'{soda}: {calories}') Coke: 90 Coke_zero: 0 Pepsi: 94

Question 37

Returns a view object of the dictionary's keys.

Answer 37

my_dict.keys() num_calories = dict(Coke=90, Coke_zero=0, Pepsi=94) for soda in num_calories.keys(): print(soda) Coke Coke_zero Pepsi

Question 38

remove the element associated with a specified key from a dictionary

Answer 38

my_dict.pop(key)

Question 39

remove an abitrary key value pair from a dictionary

Answer 39

my_dict.popitem()

Question 40

Return the value of the specified key if it exists, otherwise set it to a default value

Answer 40

my_dict.setdefault(key, value)

Question 41

Returns a view object of the dictionary's values.

Answer 41

my_dict.values() num_calories = dict(Coke=90, Coke_zero=0, Pepsi=94) for calories in num_calories.values(): print(calories) 90 0 94

Question 42

iterate through a list using the list comprehension syntax

Answer 42

new_list = [expression for loop_variable_name in iterable] my_list = [10, 20, 30] list_plus_5 = [(i + 5) for i in my_list]

Question 43

collect optional parameters into an arbitrary argument list for a function

Answer 43

*args def print_sandwich(bread, meat, *args): print(f'{meat} on {bread}', end=' ') if len(args) > 0: print('with', end=' ') for extra in args: print(extra, end=' ') print('') print_sandwich('sourdough', 'turkey', 'mayo') print_sandwich('wheat', 'ham', 'mustard', 'tomato', 'lettuce')

Question 44

collect optional parameters associated with keywords into an argument list for a function

Answer 44

def print_sandwich(meat, bread, **kwargs): print(f'{meat} on {bread}') for category, extra in kwargs.items(): print(f' {category}: {extra}') print() print_sandwich('turkey', 'sourdough', sauce='mayo') print_sandwich('ham', 'wheat', sauce1='mustard', veggie1='tomato', veggie2='lettuce')