Chapter 4

Question 1

Programs are composed of what?

Answer 1

Modules.

Question 2

Modules contain _____________?

Answer 2

Statements

Question 3

Statements contain ______________?

Answer 3

Expressions

Question 4

Expressions _______ and __________ objects

Answer 4

Create, and process

Question 5

What are literals?

Answer 5

The expressions that generate objects

Question 6

Everything that is processed in python is an ________?

Answer 6

Object.

Question 7

Strings are used to store __________ __________ as well as __________ _________ of ________.

Answer 7

Textual information, arbitrary collection ,bytes

Question 8

items in sequences are located and fetched using by their ______________?

Answer 8

relative position

Question 9

Strictly speaking strings are sequences of _________ __________.

Answer 9

one character strings

Question 10

if S = “Spam”, how would I return the length of hte string?

Answer 10

len(S).

len() is a built in functin in python.

Question 11

With the string S=”Spam” what would the expression S[0} return?

Answer 11

“S”

Question 12

Define what an index of a sequence is .

Answer 12

is a numbering system to identify the position of a charater in a sequence. always starts with 0.

Question 13

Python variable never need to be _______ ahead of time?

Answer 13

declared.

Question 14

Indexing is based on a ___________?

Answer 14

zero based position.

Question 15

a variable is created when i _______ a _________ to it.

Answer 15

assign, value

Question 16

positive indexes count from the ________. while negative indexes count from the _________.

Answer 16

front, back.

Question 17

Slices are a way to extract an entire _________ from a string in a single step.

Answer 17

column

Question 18

the form for slices X[ I :J] means what ?

Answer 18

give me everything from X from the offset I up to but not including offset J.

Question 19

if S=”Spam” what does S[:3] return?

Answer 19

‘Spa’

Question 20

if S=”Spam” . What does S[:] return?

Answer 20

‘Spam’

Question 21

with respect to strings . how would i explain concatenation?

Answer 21

joining two strings to make one new string

Question 22

With respect to strings,how would i explain repetition?

Answer 22

making a new string by repeating another.

Question 23

if I had the string S=”Spam” and “xyz” how would i make them one string?

Answer 23

S+’xyz’

Question 24

how would i repeat the string S=”Spam” 8 times and make a new string?

Answer 24

S * 8

Question 25

describe the meaning of + for numbers and strings

Answer 25

for numbers it means addition. | for strings it means concatenation.

Question 26

polymorphism in pythons means what?

Answer 26

the meaning of the operation depends on the objects being operated on.

Question 27

Every string operation is defined to produce a new string as its result, because every string is _______ in python.

Answer 27

immutable.

Question 28

what does immutable mean?

Answer 28

something cannot be changed in place after it has been created.

Question 29

What core types of objects are immutable?

Answer 29

- numbers , strings , and tuples.

Question 30

immutability can be used so that you can guarantee that an object will remain _________throughout your program.

Answer 30

constant.

Question 31

descibe a method , w.r.t. a string.

Answer 31

functions attached to the object, which are triggered with a call expression.

Question 32

String methods are the _____ ______ of ___________n tools in python.

Answer 32

first line, test-processing.

Question 33

if S="Spam". what does S.find ('pa') return? , why?, and what happens to the original string?

Answer 33

1, ;because the method used is looking for the number of 'pa" found in the string "Spam" ;The original string remains unchanged because strings are immutable. we simply created a new string.

Question 34

if S="Spam". what does S.replace('pa', 'XYZ' ) return? and why?

Answer 34

"SXYZm"

Question 35

If I have a String line = ' aaa,bbb,ccc,dd' what does the code line.split(',') return?

Answer 35

[ 'aaa' , 'bbb', 'ccc' , 'dd' ].

Question 36

If I have a String line = ' aaa,bbb,ccc,dd' what does the code line.upper() return?

Answer 36

'AAA,BBB,CCC,DD'.

Question 37

string have an advanced substitution operation known as _________?

Answer 37

formatting.

Question 38

if i have the following : '%s , eggs , and %s' % ('spam' , 'SPAM') what will be returned?

Answer 38

'spam , eggs, and SPAM'

Question 39

if i have the following : '{1}, eggs , and {0}, {2}' .format('spam' , 'SPAM', 'Spam') what will be returned?

Answer 39

'SPAM, eggs and spam Spam

Question 40

If i have the string S='Spam'. what built in function will return the attributes of the object S='Spam'.

Answer 40

dir() function. - example: >>> dir(S) - because methods are function attributes.

Question 41

With the string S= 'A\nB\tC'. what does the \n and \t stand for? and and if I perform the print(S) action what does it return?

Answer 41

- \n for end of line -\t for tab. -A B C

Question 42

Lists are also __________?

Answer 42

Sequences. ##Therefore all the operations that work with sequences also work on lists

Question 43

Education: *The Python list object is the most general sequence provided by the language. *lists are positionally ordered collections of arbitrarily typed objects , They also have no fixed size.

Answer 43

Education: *Lists are mutable---unlike strings. lists can be changed in place by assignment to offsets as well as a variety of list method calls .

Question 44

lists are _______ order ___________ of __________ typed objects. they also have ___ fixed ______ .

Answer 44

positionally , collections, arbitrarily, no, size.

Question 45

Becuase list are sequences , list support all the _________ ___________ so far discussed.

Answer 45

sequence operations

Question 46

if L = [ 123, 'spam' , 1.23 ] what does the command len(L) return?

Answer 46

3

Question 47

if L = [123 , 'spam', 1.23] what does L[0} return?

Answer 47

123

Question 48

do list have a type constraint?

Answer 48

``` no # which means a list can have strings , integars, floating point numbers . ```

Question 49

if I have the list L = [123 , 'spam', 1.23], how would I add 'NI' to the list ?

Answer 49

L.append('NI')

Question 50

if I have the list L = [123 , 'spam', 1.23] what does L.append('NI') return?

Answer 50

>>> [123 , 'spam', 1.23, 'NI'] Notice that the append method expands the list size and inserts the object at the end of the list.

Question 51

if L = [123 , 'spam', 1.23] what does L.pop(2) do?

Answer 51

``` it returns >>> 1.23 # shrinking: delete an item based on the given offset. ```