Module 3: Boolean Values, Conditional Execution, Loops, Lists and List Processing, Logical and Bitwise Operations

Question 1

2 == 2.

Answer 1

True
It’s possible to compare an integer with a float

Question 2

What kind of an operator is the == operator? (and ‘<’ ‘>’ ‘!=’ ‘<=’ ‘>=’ )
What will be the output of these operators

Answer 2

It is a binary operator with left-sided binding. It needs two arguments and checks if they are equal.

Output will be True or False

Question 3

The operator priority table

Answer 3

Priority Operator
1 ~, +, - unary
2 **
3 *, /, //, %
4 +, - binary
5 «,&raquo_space;
6 <, <=, >, >=
7 ==, !=
8 &
9 |
10 =, +=, -=, *=, /=, %=, &=, ^=, |=,&raquo_space;=, «=

Question 4

What build in functions return the largest and smallest number in a list or multiple variables?

Answer 4

max(<vars>)
Example:
>>>var = [0,2,5,7,6,2,7,8,5]
>>> max(var)
8</vars>

Question 5

x = 1
y = 1.0
z = "1"

if x == y:
    print("one")
if y == int(z):
    print("two")
elif x == y:
    print("three")
else:
    print("four")

Answer 5

one
two

Question 6

Is it possible to print multiple lines with one print statement?

Answer 6

Yes, uses “”” (3qoutes)
print(
“””
+================================+
| Welcome to my game, muggle! |
| Enter an integer number |
| and guess what number I’ve |
| picked for you. |
| So, what is the secret number? |
+================================+
“””)

Question 7

>>> test_dict = {1: 'Foo', 2: 'bar'}
>>> print(*test_dict)

Answer 7

1 2

Question 8

What’s the difference between break, continue and pass?

Answer 8

Break: exits the loop
Continue: stop this itteration of the loop and start the next (skip)
Pass: no impact on code, mostly used as placeholder when working on new code

Question 9

for i in range(2, 1):
    print(i)
else:
    print("else:", i)

Answer 9

NameError: name ‘i’ is not defined

The control value of the loop is not available after the loop if the loop is not executed

Question 10

What is the output of the following code?
~~~
n = 3

while n > 0:
print(n + 1)
n -= 1
else:
print(n)
~~~

Answer 10

4
3
2
0

Question 11

What is the output of the following code?
~~~
for num in range(4):
print(num - 1)
else:
print(num)
~~~

Answer 11

-1
0
1
2
3

Question 12

for i in range(0, 6, 3):
    print(i)

Answer 12

0
3

Question 13

Logical operators and there priority
Conjunction
Disjunction
Negation

Answer 13

And (Low priority)
Or (Low priority)
not (High priority, same as unary)

Question 14

What is the output of the following code?
~~~
not (p and q) == (not p) or (not q)
not (p or q) == (not p) and (not q)
~~~

Answer 14

True
True

Question 15

Bitwise operators:
bitwise conjunction (And)
bitwise disjunction (Or)
bitwise negation (Not)
bitwise exclusive or (xor)

Answer 15

& (ampersand) requires exactly two 1s to provide 1 as the result
(bar/ pipe) requires at least one 1 to provide 1 as the result;
~ (tilde)
^ (caret) requires exactly one 1 to provide 1 as the result

Question 16

What is the output of the following code?
~~~
»> a = 1.
»> b = 1
»> a & b
~~~

Answer 16

TypeError: unsupported operand type(s) for &: ‘float’ and ‘int’

Bitwise operators can only be used on integers

Question 17

How to check the state of a specific bit?
How to set the specific bit to 1
How to set the specific bit to 0

Answer 17

& with a mask
| with a mask
^ with a mask

with a mask

Question 18

What happens when you bitshift an odd number
17>>1

Answer 18

It will be floor deviced, because the result must be an integer
8

Question 19

x = 4
y = 1

a = x & y
b = x | y
c = ~x  # tricky!
d = x ^ 5
e = x >> 2
f = x << 2

print(a, b, c, d, e, f)

Answer 19

0 5 -5 1 1 16

Question 20

len(25)

Answer 20

TypeError: object of type ‘int’ has no len()

Question 21

How to remove an element from a list

Answer 21

This is done with an instruction named del (delete). Note: it’s an instruction, not a function.
So no ()
~~~
testlist = [1,8,6,12,8]
del testlist[2]
print(testlist) # [1,8,12,8]
~~~

Question 22

How to insert a value in a list
What happens if you use a location out of range?

Answer 22

list.insert(location, value)

It will insert the value at the last position

Question 23

my_list = []  # Creating an empty list.

for i in range(5):
    my_list.insert(0, i + 1)

print(my_list)

Answer 23

[5, 4, 3, 2, 1]

Question 24

```

What will be the output of:
~~~
lst = []
del lst
print(lst)
~~~

Answer 24

NameError: name ‘lst’ is not defined

Question 25

What will be the output of:
~~~
lst = [“D”, “F”, “A”, “Z”]
lst.sort()
~~~

Answer 25

Nothing, the .sort method works inplace, it has no output.

Question 26

list_1 = [1]
list_2 = list_1
list_1[0] = 2
print(list_2)

Answer 26

[2]
Because the name of the var is only used to point to a memory location
Slicing is coping the content to a new memory location

Question 27

list_1 = [1]
list_2 = list_1[:]
list_1[0] = 2
print(list_2)

my_list = [10, 8, 6, 4, 2]
new_list = my_list[1:3]
print(new_list)

Answer 27

[1]

[8, 6]

With slicing the last index is the end number -1

Question 28

my_list = [10, 8, 6, 4, 2]
new_list = my_list[-1:1]
print(new_list)

```
my_list = [10, 8, 6, 4, 2]
new_list = my_list[3:]
print(new_list)
~~~

Answer 28

[]
Because if the start is further than the end it will return a empty list
[4, 2]

Question 29

my_list = [10, 8, 6, 4, 2]
del my_list[:]
print(my_list)

```
my_list = [10, 8, 6, 4, 2]
del my_list
print(my_list)
~~~

Answer 29

[]
NameError

Question 30

my_list = [0, 3, 12, 8, 2]

print(5 in my_list)
print(5 not in my_list)
print(12 in my_list)

Answer 30

False
True
True

Question 31

list_1 = ["A", "B", "C"]
list_2 = list_1
list_3 = list_2

del list_1[0]
del list_2

print(list_3)

Answer 31

['B', 'C']

Question 32

list_1 = ["A", "B", "C"]
list_2 = list_1
list_3 = list_2

del list_1[0]
del list_2

print(list_3)

Answer 32

['B', 'C']