Quiz 1

Question 1

len(list)

Answer 1

Returns the length of a list or any collection.

Question 2

type(variable)

Answer 2

Identifies the type of the variable.

Question 3

isinstance(variable, type)

Answer 3

Checks if a variable is of a specific type.

Question 4

append(element)

Answer 4

Adds an element to the end of the list.

Question 5

insert(index, element)

Answer 5

Inserts an element at a specific position.

Question 6

pop(index)

Answer 6

Removes and returns an element at the specified index.

Question 7

sort()

Answer 7

Sorts the list in ascending order.

Question 8

slice notation [start:stop:step]

Answer 8

Access specific portions of a list.

The first possible position is 0, and the slice will get elements up to, but not including stop.

Question 9

dict[key] = value

Answer 9

Adds or updates a key-value pair

Question 10

del dict[key]

Answer 10

Removes the key-value pair with the given key.

Question 11

dict.pop(key)

Answer 11

Removes and returns the value for the specified key

Question 12

dict.keys()

Answer 12

Returns a list of all keys in the dictionary.

Question 13

dict.values()

Answer 13

Returns a list of all values in the dictionary.

Question 14

set_one.union(set_two)

Answer 14

Returns a new set with elements from both sets.

Question 15

set_one.intersection(set_two)

Answer 15

Returns a set with elements common to both sets.

Question 16

set_one.difference(set_two)

Answer 16

Returns elements in set_one but not in set_two.

Question 17

int()

Answer 17

Converts a value to an integer.

Question 18

float()

Answer 18

Converts a value to a float.

Question 19

str()

Answer 19

Converts a value to a string.

Question 20

bool()

Answer 20

Converts a value to a boolean.

Question 21

Math Module Functions:

Answer 21

1. math.log(x): Returns the natural logarithm of x.
2. math.exp(x): Returns the exponential of x.
3. math.ceil(x): Rounds x up to the nearest integer.
4. math.floor(x): Rounds x down to the nearest integer.

Question 22

Variable types

Answer 22

integer: whole number
float: not whole number
string: text
boolean: true or false

Question 23

Tuples

Answer 23

• Tuples are quite similar to lists in that you access elements by position, but they are “fixed.”
• You can’t change the number of elements in the tuple.
• You can’t change the objects stored in each slot.
• The formal term is that they are “immutable”. It is like they are set in concrete.

Question 24

Container types

Answer 24

– list
– dict
– tuple
– set

Question 25

Lists

Answer 25

• variable length container, within which the elements can be modified (mutable – compare to a tuple later).
• It can contain a mix of variable types.
• It can be “nested”, where elements inside the list are themselves other containers.
• List elements can be accessed by position (starting at 0)

Question 26

Dicts

Answer 26

• A dict contains “key-value” pairs.
• You don’t access a dict by position (unlike a list), but rather by the name of the key.
• This can be much more efficient for looking up values, rather than maintaining and searching lists.
• To create a dict directly use curly braces {}.

Question 27

Set container

Answer 27

• has no ordering (so you can’t access it by position), and its elements are unique.
• Which is the same as a set in mathematics.
• Like a dict, they can be created using the curly brackets {}.
• They can also be created by using the set function.
• The set is mutable, but its elements must be immutable.

Question 28

Which container should you use?

Answer 28

• This will be very dependent on the objective of the problem.
• A dictionary is going to be useful when you are frequently looking up values by name.
• A list will be useful, when there is an ordered type structure to the underlying data and you are looking
  things up by position.