Python core basics

Question 1

How to check if element exists in list or not?

Answer 1

print(1 in L)

Question 2

Adding new list to an existing list without creating a new temporary list

Answer 2

l.extend([1,2])

Question 3

What is the difference between append and extend

Answer 3

In case of append : We will be adding that component as recieved in the input parameters
Whereas in case of extend , it will take the individual components from that list and then add it to the list
Example:
l.append([2,5])
This adds [2,5 ] aka [1,[2,5]]
l.extend([2,5])
The adds 2 and 5 to the list [1,2,5]

Question 4

How do we delete a certain component in list

Answer 4

del L[0]

Question 5

How to remove element by passing object itself instead of index of that object in the list

Answer 5

L.remove(“Physics”)

Question 6

Syntax for removing the last element from a list

Answer 6

L.pop()

Question 7

What happens if you do B= A.sort() where A and B are lists

Answer 7

A returns the new sorted list
A=[3,4,2] -> A=[2,3,4]
while B returns nothing .
Because its a worthless piece of shit. JK A.sort() is a void function and only changes A, it doesent return an object in return. Only changes the list which is calling the function .

Question 8

Syntax to sort a list in descending order

Answer 8

L.sort(reverse=True)

Question 9

What happens if you sort out list which contains words instead of numbers

Answer 9

It arranges the words inside the list in lexographic fashion

Question 10

Syntax to sort a particular list and store within itself

Answer 10

L.sort()

Question 11

Syntax to sort a particular list and return list to an object

Answer 11

sorted(L)

Question 12

What is the difference between lists and tuples?

Answer 12

Lists are immutable , meaning you can access as well as change individual elements
tuples are immutable, meaning while you can access the individual elements , you cant change them.

Question 13

How do we copy A to B WITHOUT both of them being linked by refence.
or rather
Copying only the elements and maintain them independent of each other… making sure that One is not affected by changing the other

Answer 13

A= [1,2,3]
B= A[:]
B[0]=3
A=[1,2,3] , B=[3,2,3]

Question 14

If B=[1,2,3]
A = B
B[0] = 3
Then what will be A,B?

Answer 14

A , B will be the same because when we use A=B they are connected by references rather than different objects.
A= [3,2,3]
B= [3,2,3]

Question 15

What is the syntax if I want to maintain a sorted list as a different object (aka different from the original list object)

Answer 15

C= sorted(A)
A -> Non sorted list Ex : [2,3,1]
C-> Sorted List Ex : [1,2,3]

Question 16

What is difference between sets, tuples and lists

Answer 16

Sets are mutable BUT we can not index. (they also DO NOT store duplicates)
Lists are mutable and can be indexed
Tuples are immutable but can still be indexed.

Question 17

Finding min of all elements in list or tuple

Answer 17

min(lis) or min(t)

Question 18

Concatenating tuples

Answer 18

tup3 = tup2 + tup1

Question 19

finding sum of all elements in a tuple or list

Answer 19

sum(lis) or sum(t) //List or tuple

Question 20

Finding max of all elements in list or tuple

Answer 20

max(lis) or max(t)

Question 21

What happens if I do this
t=(1,2,3)
y= t+4,

Answer 21

It will raise and error because by order precedence rule first it will try to add 4 .But it cant because its an individual element.

In order for the above statement to work , you need to do
y= t+ (4,)
Then by order precedence (4,) will instantiate tuple and then finally concatenate it

Question 22

t= (2,3,4)

What happens if I print(t[-1:-2])

Answer 22

It wont raise an error , it will return back an empty tuple
()
The same goes for list

Question 23

What happens if a tuple or list has both numbers and non numbers and you try to apply sum or min or max?

Answer 23

It returns me error

Question 24

Can you add element to a tuple via append or extend()

Answer 24

No , you CAN add a tuple to a tuple using concatenation but you CANT add individual elements to a tuple using functions or operator.

Question 25

What is packing and unpacking in tuples?

Answer 25

Instantiating vairables
a = (1,2,3) -> Comes under packing
(f,g,h) = (1,2,3) or (f,g,h)=a
The above line comes under unpacking because youre unpacking the elements and assigning values

Question 26

Since tuples are immutable , can they still be sorted ?

Answer 26

Yes , they can be sorted via sorted(t)
The returning object is list .
And if we want to turn the list into tuple we can do 
y = sorted(t) ///y is list
tuple(y) ///Which will return tuple

Question 27

Syntax for converting list in to tuple

Answer 27

lis = [1,2,3]
t= tuple(lis)

Question 28

How to change list to sets

Answer 28

set(Grades)

Question 29

How do we initiate sets?

Answer 29

s = {1,2,3,4,5,4}

which will store s= s = {1,2,3,4,5}

Question 30

How do we add new elements in sets?

Answer 30

s.add(1)

Question 31

How do we remove objects in sets via object itself?

Answer 31

a.remove(‘Hello’) //We are removing by passing object not index

Question 32

How do we perform union of 2 sets?

Answer 32

A = {1,2,3,4}
B= {5,6,7,8}
print(A|B) (OR) print(A.union(B))

Question 33

How do we perform intersection of 2 sets?

Answer 33

A = {1,2,3,4}
B= {5,6,7,8}
print(A & B) (Or) A.intersection(B)

Question 34

Remove elements of B from A

Answer 34

A = {1,2,3,4}
B= {3,4,7,8}
A-B (or) A.difference(B)
Output : {1,2}

Question 35

Print all the elements except the intersection of both elements

Answer 35

A = {1,2,3,4}
B= {3,4,7,8}
print(A^B)
Output : {1,2,7,8}

Question 36

What is one of the major differences between sets and lists and tuples in terms of operation complexity?

Answer 36

Sets are the fastest means to serach through and fetch data compared to other 2