Chap 8 - programing python - print, if/elif/else, (nested) loops, len, string manipulation, arrays

Question 1

name 6 data types

Answer 1

-integer
-string
-boolean
-float
-character (char)
-date

Question 2

how do you use the print function

Answer 2

print(“ “)

Question 3

2 ways you can print messages on print function

Answer 3

-comma
-concatenation (adding)

Question 4

meaning of concatenation

Answer 4

join together

Question 5

how do you use comma when printing

Answer 5

use comma between words

Question 6

how do you use concatenation when printing

Answer 6

use ( + ) to add the strings

Question 7

what is the difference between using comma and concatenation

Answer 7

space in comma, no space in concatenation

Question 8

can you add strings

Answer 8

yes

Question 9

can you add integers

Answer 9

no

Question 10

what must you put when using \t and \n

Answer 10

quotations because they’re strings

Question 11

what does \t do

Answer 11

a tab of space

Question 12

what does \n do

Answer 12

a new line

Question 13

what does = do

Answer 13

assignment of variable

Question 14

what does != mean

Answer 14

not equal

Question 15

3 rules for variables

Answer 15

-has to start with a char
-case sensitive
-no special char and spaces - willc hange program (except underscore)

Question 16

arithmetic operation for
-addition
-subtraction
-multiply
-divide
-remainder
-power
-squared

Answer 16

• +
• -
• *
• / (float), // (integer)
• %
• **
• **(1/2)

Question 17

relational operation for:
-greater than
-greater than or equal
-smaller than
-smaller than or equal
-equal (Equality (eg, 2 obj, same 2 content))
-not equal (Equality (eg, 2 obj, same 2 content))

Answer 17

• >
• > =
• <
• <=
• ==
• !=

Question 18

logical operators

Answer 18

• and
• or
• not
  eg. if not hungry:

Question 19

note: explain each thing when explaining assignment

Answer 19

eg. c = a + b
- c: variable
- +: addition of a and b
- =: assignment of variable

Question 20

equality vs identity vs memebership

Answer 20

equality - checks if obj has same contents (2 obj, same 2 content)
identity - check if obj are the same by refer back to same memory (2 obj, 1 content)
membership - check if value exists in a sequence

Question 21

what does = & == do

Answer 21

= - assignment of variables
== - comparison

Question 22

how do you find input for diff data types

Answer 22

str(input(“ “))
int(input(“ “))
float(input(“ “))

Question 23

1)can integer be stored in float, why
2)can float be stored in integer, why

Answer 23

1)yes, integer requires less memory than float
2)no, float requires more memory than integer

Question 24

what is the drawback of integer and float stored as string

Answer 24

they’ll be used as a string - lose their properties (can’t do mathematical operations on them)

Question 25

1)can integer and float be stored in string
2)can a string be an integer/ float

Answer 25

1)yes
2)no

Question 26

how do you use if, elif, else conditional statement

Answer 26

if ( ):
, start here
-indentation
elif ( ):
, start here
-indentation
else:
, start here
-indentation

Question 27

how do you use nested ifs

Answer 27

if ( ):
if ( ):
-indentation

Question 28

how do you use and & or conditions in conditional statements

Answer 28

eg. if ( age> 10 and age< 20):
eg. if ( age> 10 or age< 20):

Question 29

how do you use conditional statement to get something in between value

Answer 29

eg. if (0 < username <10):

Question 30

nota: % - remainder, // - integer, / - float (for division)

Question 31

note: all chars are strings, not all strings are chars

Question 32

Iteration

Answer 32

looping

Question 33

why are looped required

Answer 33

use same algorithm for diff. inputs

Question 34

types of loops

Answer 34

-for
-while

Question 35

basic structure of loops

Answer 35

-initializer- variable which controls if loop is done or not
-action
-stopping condition
-updating counter/ no. loops

Question 36

how to write for loop

Answer 36

-for i in range (__,__,_if you want__):
-for i in (variable/ list/ str)
-third one changes the steps between the loop
-don’t need to write iterating variable at start
(i changed to elements in variable/ list/ str)
(auto counter update)

Question 37

how to update counter

Answer 37

i = i+1
i +=1

Question 38

how to write while loop

Answer 38

i = 0
while (____):
i +=1
(manuel counter update)

Question 39

how does range function work

Answer 39

eg, (0, 5) - no.s - 0, 1, 2, 3, 4, - no 5
(0, 20, 2) - no.s 0-19, with 2 step btw (eg, 0, 2, 4…)
(variable/ list/ str) = no.s in that variable, list

Question 40

diff btw for & while loops

Answer 40

-for - knows how many times to run = count controlled
-while - checks iterating value before running = precondition

Question 41

types of loop control statements

Answer 41

-break
-continue
-pass

Question 42

how to use break loop control

Answer 42

-write break within loop
-stop loop
-if used in nested loop, it stop the inner most loop

Question 43

how to use pass loop control

Answer 43

-write pass within loop
-acts as a placeholder and doesn’t print the i for that loop

Question 44

how to use continue loop control

Answer 44

-write continue within loop
-skips current iteration and jumps to next loop

Question 45

how to write loop/if/elif with a list as its range

Answer 45

n= [“A”, “B”]
-for i in n:
-while i in n:
-if variable[i] in n:
note: i changes to elements in list, list can be any data type

Question 46

index values in list

Answer 46

-all char has an index value
-first element = 0 - positive
-last element = -1 - negative
-space also has an index value

Question 47

note: space is considered a char so has an index value

Question 48

how to use len function

Answer 48

-finds no. elements in a list - list can be of any data types
n = [1,2,3]
length = len(n)
print(length)

Question 49

how to extract a certain char from a list

Answer 49

num = [1,2,3,4]
- print(num[ 0 ]) = 1
-print(num[ 0: ]) = 1, 2, 3, 4
-print(num[ 0:2]) = 1,2 (index after : not included)
-print(num[:2]) = 1,2 (index after : not included)
-print(num[-1]) = 4
-print(num[i:i+ n ]) = value with i index & n no.s after it

Question 50

diff btw in range of loops -

Answer 50

-for i in range (10, lengthData+10):
= i starts from 10th index - if range i beyond elements in list = index out of range error
-for i in range (0, lengthData):
= i starts from 0th index

Question 51

how to print i in a single line in a loop

Answer 51

print( i, end=” “)

Question 52

how to use match case statements

Answer 52

match (variable):
case “something”:
action
case _:
action (only run when none of others match)
-use like if statements

Question 53

define array

Answer 53

-a sequence of elements of the same data type

Question 54

what the the index value of first element called

Answer 54

lower bound

Question 55

what the the index value of last element called

Answer 55

upper bound

Question 56

how do you create a blank 1D array

Answer 56

-reserving memory in ram
-variable = [ None ] * (number of times)

Question 57

how to use blank array and string manipulation together

Answer 57

-variable [index number] = “ “
-for i in range ( , ):
variable [i] = ______
-while i < ___:
variable [i] = ______

Question 58

note: there are index values for each element in an array

Question 59

2 types of searching algorithms

Answer 59

-linear search
-binary search

Question 60

1 type of sorting algorithm

Answer 60

-bubble sort

Question 61

how does linear search work & its time

Answer 61

-compare target value with elements from left to right until they match (can be sorted or unsorted list)
-time: 0(n)

Question 62

advantages and disadvantages of linear search

Answer 62

advantages:
-fast for small to medium data sets
-works for sorted & unsorted sets
-good for data structures with no random access
disadvantages:
-slow for large data sets

Question 63

how does binary search work & its time

Answer 63

-check if target value if equal, bigger or smaller than the element in the middle
-eg, it’s smaller so all the elements smaller than the mid element and the mid element are left out in the next search
-continue until target value is found
-time: 0 (log n)

Question 64

advantages and disadvantages of binary search

Answer 64

advantages:
-quick
-good for large data sets
disadvantages:
-needs to be sorted

Question 65

how does bubble sort work & its time

Answer 65

-start with 1 chosen element
-compares adjacent elements to the chosen element and swaps them if needed until it is no longer needed
-time: 0 (n^2)

Question 66

advantages and disadvantages of bubble sort

Answer 66

disadvantages:
-bad for large data sets

Question 67

how to do nested for loops

Answer 67

-2 counters for inner and out loops
-outer loop only loops after inner loop is finished
eg. for j in range (0,3):
for i in range (0,2):
action

Question 68

what variable can you use for bubble sort

Answer 68

a temporary variable for the element swapping process

Question 69

Code for bubble sort

Answer 69

n = len(array)
for i in range(n - 1):
for j in range(n - i - 1):
if array[ j ] > array[ j + 1 ]:
temp = array[ j ]
array[ j ] = array[ j + 1]
array[ j + 1] = temp

Question 70

code for linear search

Answer 70

for i in range (len(array)):
if array[ i ] == number:
print(“number found”)

Question 71

code for sum of reach row in 2D array

Answer 71

for row in range ( , ):
sum = 0
for column in range( , ):
sum += array[row] [column]
print(sum)

Question 72

code to put highest/ lowest/ avg value from 2D array in 1D array

Answer 72

highest_stores = [0 for i in range( )]
salary = [[0 for c in range( )] for r in range( )]
for r in range ( , ):
highest_salary = salary[r] [c]
for c in range ( , ):
if salary[r] [c] > highest_salary:
highest_salary = salary[r] [c]
highest_stores[r] = highest_salary
print(“Highest salary in”, r, “is”, highest_salary[r])
-declare the first element in each row as highest salary & compare it with others
-if others are bigger, highest salary is replaced by it

Question 73

how to swap elements without a temporary variable

Answer 73

-ages [i], ages [i+1] = ages [i+1], ages [i]
1 2 2 1
Left to right:
1 goes to 2
2 goes to 1

Question 74

How does a post test loop work (not used in python)

Answer 74

-initialize loop counter
-execute action
-update counter
-check condition
-if condition met, stop
else repeat

Question 75

how does a pre test loop work

Answer 75

-initialize loop counter
-check condition
if condition met:
-execute action
-update counter

Question 76

note: arrays cannot be implemented on python so just think of them like list with 1 data type

Question 77

what is a 2D list

Answer 77

a list made up of lists
eg.
meats = [“chicken”, “fish”, “turkey”]
groceries = [fruits, groceries, meats]

Question 78

how to use a 2D list with variables to print row or element

Answer 78

for a row:
-print(groceries [row])
for a single element:
-print(groceries [row] [column])

-each list is a row, each element is in a column (like a table)

Question 79

define traversing

Answer 79

accessing individual elements in 2D array

Question 80

how to traverse

Answer 80

groceries = [[“apple”, “orange”, “banana”, “coconut”],
[“celery”, “carrots”, “potatoes”],
[“chicken”, “fish”, “turkey”]]
-for j in groceries:
for i in j:
print(i)
-for row in range ( , ):
for column in range ( , ):
print(groceries [row] [column])
-finish inner loop before changing outer loop
row, column:
0, 0
0, 1
1, 0
1, 1

Question 81

what does end = “ “ do

Answer 81

rearranges the printed word in a single line

Question 82

note: for loop doesn’t check condition, only runs it

Question 83

pre- condition loop in pseudocode

Answer 83

while loop

Question 84

post- condition loop in pseudocode

Answer 84

REPEAT

Question 85

what is size of array

Answer 85

number of elements

Question 86

how to randomly choose an element

Answer 86

import random
random.choice( )
random.randint( ) / random.randstr ( ) / random.randfloat ( )

Question 87

how to add time

Answer 87

import time
time.sleep( )
-in seconds

Question 88

what happens if index is too big

Answer 88

index out of range error

Question 89

how to create empty 2D array

Answer 89

array = [ [ 0 for column in range ( , )] for row in range ( , )]
-can replace 0 with None or “ string” to fill in the blank array

Question 90

order of row & column in 2D array when:
1)creating array
2)printing array
3)traversing
mark row = 1, column = 2

Answer 90

1) column, row 2, 1
2) row, column 1, 2
3) row, column 1, 2

Question 91

what can you do with traversing

Answer 91

-print each elements
-add data into 2D array eg. input or adding

Question 92

difference between for i in range ( , ) & for i in array when comparing & printing Found/ Not found

Answer 92

for i in range ( , ):
-print Found/ Not found as many times as range
for i in array:
-print Found/ Not found 1 time

Question 93

note:
before making 2D array - make a table look alike of it
mark row = 1, column = 2

Question 94

difference btw 1D & 2D array in terms of memory

Answer 94

1D - data is stored randomly in memory cell = more comparisons to find them
2D - data is stored consecutively in memory cell = less comparisons to find them

Question 95

help for arrays:
https://docs.google.com/document/d/1b5Tt-2W5yVyTZYWSwUQk3DXtFnfM_McnkaAZX1FV1QQ/edit?tab=t.0#heading=h.isd4beaopm41

Question 96

note:
for loop - limited running
while - unlimited running