Chapter 11

Question 1

if a=[1, 2, 3] and b=[1,2,3] do and b point to the same object?

Answer 1

no

Question 2

if a=[1,2,3] and b=a, do b and a point to the same object?

Answer 2

yes

Question 3

aliases

Answer 3

Multiple variables that contain references to the same object.

Question 4

clone

Answer 4

To create a new object that has the same value as an existing object. Copying a reference to an object creates an alias but doesn’t clone the object.

Question 5

delimeter

Answer 5

A character or string used to indicate where a string should be split.

Question 6

element

Answer 6

One of the values in a list (or other sequence). The bracket operator selects elements of a list. Also called item.

Question 7

immutable data value

Answer 7

A data value which cannot be modified. Assignments to elements or slices (sub-parts) of immutable values cause a runtime error.

Question 8

index

Answer 8

An integer value that indicates the position of an item in a list. Indexes start from 0.

Question 9

item

Answer 9

See element.

Question 10

list

Answer 10

A collection of values, each in a fixed position within the list. Like other types str, int, float, etc. there is also a list type-converter function that tries to turn whatever argument you give it into a list.

Question 11

list traversal

Answer 11

The sequential accessing of each element in a list.

Question 12

modifier

Answer 12

A function which changes its arguments inside the function body. Only mutable types can be changed by modifiers.

Question 13

mutable data value

Answer 13

A data value which can be modified. The types of all mutable values are compound types. Lists and dictionaries are mutable; strings and tuples are not.

Question 14

nested list

Answer 14

A list that is an element of another list.

Question 15

object

Answer 15

A thing to which a variable can refer.

Question 16

pattern

Answer 16

A sequence of statements, or a style of coding something that has general applicability in a number of different situations. Part of becoming a mature Computer Scientist is to learn and establish the patterns and algorithms that form your toolkit. Patterns often correspond to your “mental chunking”.

Question 17

promise

Answer 17

An object that promises to do some work or deliver some values if they’re eventually needed, but it lazily puts off doing the work immediately. Calling range produces a promise.

Question 18

pure function

Answer 18

A function which has no side effects. Pure functions only make changes to the calling program through their return values.

Question 19

sequence

Answer 19

Any of the data types that consist of an ordered collection of elements, with each element identified by an index.

Question 20

side effect

Answer 20

A change in the state of a program made by calling a function. Side effects can only be produced by modifiers.

Question 21

step size

Answer 21

The interval between successive elements of a linear sequence. The third (and optional argument) to the range function is called the step size. If not specified, it defaults to 1.