Programme structure and control flow

Question 1

What does the ‘or’ expression return?

Answer 1

x or y = x if x = True else y

Question 2

What does the ‘and’ operator return?

Answer 2

x and y = y if x = True else x

Question 3

What does the ‘not’ operator return?

Answer 3

not x = True if x = False else False

Question 4

In python, an object is considered true unless either of 3 conditions hold, what are these?

Answer 4

bool(object) = False
object is empty
object has value 0

Question 5

What would [] and 100 return?

Answer 5

[]

Question 6

What would [] or 8 return?

Answer 6

8

Question 7

In python, how would you iterate over the key-value pairs of a dictionary?

Answer 7

for key, value in dictionary.items():

… do stuff …

Question 8

What is meant by variable unpacking?

Answer 8

• (a, b, c) gives a, b, c

* *{a : 1, b : 2, c : 3} gives a=1, b=2, c=3

Question 9

How would you return an exception in python?

Answer 9

try:
… code …
except Exception as e:
return e

Question 10

How would you return an exception in python?

Answer 10

try-except blocks

Question 11

Give an example of an Arithmetic error, an OS error, a Lookup error and a syntax error.

Answer 11

1 / 0
reading non-existent file
'string'[100000]
    for i in range(10):
print(i)