Chapter 4 - For loops, Strings, and Tuples

Question 1

an ordered list of things

Answer 1

a sequence

Question 2

All sequences are made up of …..

Answer 2

elements

Question 3

a sequence in which each element is one character

Answer 3

a string

Question 4

(start, stop, step)

Answer 4

range(), the end point is not included (if it’s 50, 49 is the last number included)

Question 5

find message length with…

a sequence’s length is equal to the number of elements it has.

Answer 5

len()

Question 6

differences between elements and characters

Answer 6

a space is an element but not a character

Question 7

going through a sequence one character at a time

Answer 7

sequential access

Question 8

direct access

Answer 8

random access

Question 9

you can specify a position in a sequence and get the element at that position

Answer 9

indexing

Question 10

[-1] negative index number

Answer 10

last character

Question 11

high = len(word)
low = -len(word)

What index positions will this produce if word = “index”
position = random.randrange(low, high)

Answer 11

-5, -4, -3, -2, -1, 0, 1, 2, 3, 4
In other words: it will produce a random number from and including the low end point, up to, but NOT including the high end point.

Question 12

the inability of strings to be changed

Answer 12

string immutability

Question 13

A variable written in ALL CAPS by convention

• more readible
• used for variable meant to be unchaning

Answer 13

constant

Question 14

a section of elements (part of a sequence)

Answer 14

a slice

Question 15

start = None

Answer 15

placeholder, evaluates to False

Question 16

slicing shorthand

Answer 16

word[:]

Question 17

type of sequence, unlike a string (which can only contain characters), it can contain elements of any type
it’s elements don’t have to be of the same type
whatever you assign to a variable, you can group together and store in a …..

Answer 17

tuple

Question 18

Can a tuple be treated as a condition

Answer 18

Yes

Question 19

Is an empty tuple treated as True or False?

Answer 19

False

Question 20

*Some programming languages offer structures similar to tuples (arrays; vectors). However, those languages usually restrict….

Answer 20

the elements of the sequences to just one type

Question 21

what does len() return when used on a tuple

Answer 21

the number of tuple elements

Question 22

Tuples: mutable or immutable?

Answer 22

immutable

Question 23

What happens during concatenation of tuples

Answer 23

The original tuple is not modified, because it is immutable. Instead, an augmented assignment operator can create a brand-new tuple with the elements from the previous tuples and assign that to (the name of the original variable [ tuple])
e. g. 
me = ("brain", "brawn")
you = ("skills", "pills")
me += you
>>>print(me)
('brain', 'brawn', 'skills', 'pills')

Question 24

message = “something”

print message backwards

Answer 24

print(message[::-1])