W16

Question 1

How to add an element to a list?

Answer 1

list.append() –> adds it to the end

Question 2

How to delete all elements of a list?

Answer 2

list.clear()

Question 3

How to copy a list?

Answer 3

import copy

x=copy.copy(list)

it copies the reference

Question 4

what does count() do in a list?

Answer 4

it returns the repetition number of a specified values

Question 5

How to find a value index in a list?

Answer 5

list.index(value)

Question 6

how to add an element at the end of a list?

how to add an element in a specified index?

Answer 6

list. append(“h”)

list. insert(6, “h”)

Question 7

pop() vs remove() vs del

Answer 7

del and pop() delete a specific index.

remove() deleted a specific value.

Question 8

sort() vs. sorted()

Answer 8

1- list.sort(), does not return anything. it just changes the original list. It one of the python list method

2- sorted(list), returns a new sorted list. It is one of the built-in functions.

both sort a list in an ascending order. to sort a list in a descending order:

list.sort(reverse = True)
sorted(list, reverse = True)

Question 9

a method to reverse the order of a list:

Answer 9

reverse()

Question 10

What are the membership operators?

Answer 10

(in) and (not in)

Question 11

monthInQuarter = [ 0 ] ∗ 10

Answer 11

One common use of replication is to initialize a list with a fixed value

Question 12

shallow copy vs. deep copy

for (2D lists, string lists and string)
int and float lists are always considered as deepcopy (check)

Answer 12

A shallow copy also makes a separate new object object or list, but it simply copies the references to their memory addresses.
(Hence, if you make a change in the original object, it would reflect in the copied object, and vice versa)

A deep copy makes a new and separate copy of an entire object or list with its own unique memory address. (Using the copy module)

Question 13

Examples of shallow and deep copy:

Answer 13

Shallow:
import copy
lst2=copy.copy(lst1)

Deep:
import copy
lst2=copy.deepcopy(lst1)

Question 14

list[i][j], what are i and j?

Answer 14

i –> column

j –> row

Question 15

to print or access a 2D list you will use nested loop, so what will the inner and outer loops print?

Answer 15

outer –> rows

inner –> columns

Question 16

how to find a list columns and rows number

Answer 16

rows == len(list)

columns == len(list[0])

Question 17

A container that stores a collection of unique values the elements or members of it are not stored in any particular order

Answer 17

set and dictionary

Question 18

True or False?

Sets can be accessed by position?

Answer 18

False, since it is not ordered

Question 19

How to create an empty set?

with values?

Answer 19

empty:
Don’t –> x= {}
Do –> x=set()

not empty:
x={1,2,3}
x=set(list)

Question 20

the number of elements in a set:

Answer 20

len(set)

Question 21

True or False:

Two sets are equal if and only if they have exactly the same elements

Answer 21

True, since the order does not matter.

Question 22

Are sets mutable or immutable?

Answer 22

sets are mutable

Question 23

how to add elements in a set?

Answer 23

add()

Question 24

add(“hello”), if hello is already exited in the set what will happen?

Answer 24

no error will occur, and the new “hello” will not be added

Question 25

how to remove an element?

Answer 25

The discard() method removes an element if the element exists, and if not It has no effect

Question 26

how to check if set1 is a subset of set2?

Answer 26

set1.subset(set2)
the order is important:
A set is a subset of another set if and only if every element of the first set is also an element of the second set

Question 27

To add two sets:

Answer 27

set1.union(set2)

Question 28

True or False:

To concatenate two sets use (+)

Answer 28

False.

set concatenation creates an error

Question 29

how to find similar values in different sets?

Answer 29

set1.intersection(set2)

returns a set of intersected values