Misc.

Question 1

//

What does the above do

Answer 1

Floor Division (returns a whole number rounded down)

The whole number could be an int or a float

Question 2

What’s the short-command for quick-save

Answer 2

Ctrl + s

Question 3

What’s the best case to use when naming .py files

Answer 3

lower-case letters with underscores

E.g.,

python_app.py

Question 4

What is the best naming convention when defining a constant

Answer 4

ALL_CAPITALS_WITH_UNDERSCORES

Question 5

How do you indent multiple lines at the same time

Answer 5

Highlight all the lines then hit tab

Question 6

When importing functions from modules, you will generally need to use dot notation, e.g.,

import processor
print(processor.function_1)

How can you import functions and NOT have to use dot notation

Answer 6

from processor import function_1

print(function_1)

Question 7

Short command for redo

Answer 7

Ctrl + Shift + Z

Question 8

are “num // num” & “math.floor(num / num)” identical

Answer 8

Both divide & round down, but…

“num // num” will return either an int or a float, but “ “math.floor(num / num)” always returns an int

Question 9

“or” returns True if either condition is true. But what if both conditions are true

Answer 9

“or” will also return True

Question 10

What does input() do

Answer 10

It pauses the program and waits for the user to type something, then returns that input as a string.

E.g.,
name = input(“What is your name? “)
print(“Hello, “ + name)

Question 11

What is the difference between “continue”, “pass”, and “break”

Answer 11

break: Exits the loop completely

continue: Skips the rest of the current loop iteration and moves to the next one

pass: Does nothing — it merely avoids syntax errors

Question 12

Return infinity

Answer 12

return float(“inf”)

or

import math
return math.inf

Question 13

Return negative infinity

Answer 13

return float(‘-inf’)

or

import math
return -math.inf

Question 14

What does abs() do

Answer 14

abs() removes the sign of the number - always making it positive (or zero)

(It does not round floats)

Question 15

lst = [1, 2, 3]

How would the two operations below affect “lst”?

lst.append([4, 5])

lst.extend([4, 5])

Answer 15

append: [1, 2, 3, [4, 5]]

extend: [1, 2, 3, 4, 5]

append() adds one thing to the end of a List.

extend() adds each item from another iterable one by one

Note that append() results in a List within a List, but extend() does not.

Question 16

lst = [1, 2, 3]

How would the two operations below affect “lst”?

lst.append([4])

lst.extend([4])

Answer 16

append: [1, 2, 3, [4]]

extend: [1, 2, 3, 4]

Append() results in a List within a List, but extend() does not

Question 17

lst = [1, 2, 3]

1) Can both of the below execute?
2) If so, or if not, why?
3) What result do they individually produce?

lst.append(4)

lst.append([4])

Answer 17

1) Yes, both can execute.
2) append() always accepts one thing — no matter what that one thing is. It doesn’t open or unpack that thing.
3) lst.append(4): [1, 2, 3, 4]
lst.append([4]): [1, 2, 3, [4]]

Question 18

lst = [1, 2, 3]

1) Can both of the below execute?
2) If so, or if not, why?
3) What result do they individually produce?

lst.extend(4)

lst.extend([4])

Answer 18

1) Only lst.execute([4]) can execute.
2) extend() requires an iterable.
3) lst.extend(4): TypeError
lst.extend([4]): [1, 2, 3, 4]

Question 19

lst = [1, 2, 3]
lst.extend((4))
print(lst)

.extend() can accept any iterable (including Tuples). However, when “lst” is printed, it returns an Error.
1) Why?
2) How can lst.extend((4)) be fixed?

Answer 19

1) Python does not recognise “4” as a Tuple just because it’s in parentheses - “4” also requires a comma after it.

2) lst.extend((4,))

Question 20

lst = [ ]
for i in 100:
lst.append(i)

Why does the above return an Error

Answer 20

100 is not an iterable

Question 21

Return 2 ways of finding the square root of 25

Answer 21

import math
return math.sqrt(25)

or

return 25 ** 0.5

Question 22

What does the filter() function do, and how do you use it?

Answer 22

filter(function, iterable) returns only the elements of the iterable for which the function returns True.

E.g.,
def is_even(num):
return num % 2 == 0

numbers = [1, 2, 3, 4, 5, 6]
evens = list(filter(is_even, numbers))

.# Result: [2, 4, 6]

Question 23

What happens if you use filter(None, iterable) in Python?

Answer 23

It filters out all falsy values from the iterable — like False, None, 0, ‘’, [], etc.

Question 24

def longer_than_three(s):
return len(s) > 3

What build-in function can be used with the function above to keep only the strings longer than 3 characters from the List “words” below.

words = [“cat”, “house”, “sun”, “planet”]

Answer 24

filter()

E.g.,
result = list(filter(longer_than_three, words))

.# Result: [‘house’, ‘planet’]

Question 25

def is_positive(n): return n >= 0 What build-in function can be used with the function above to remove all negative numbers from a the List "nums" below. nums = [-5, 3, 0, -2, 8, -1]

Answer 25

filter() E.g., non_negatives = list(filter(is_positive, nums)) ## Footnote .# Result: [3, 0, 8]

Question 26

When should I use "is" vs "=="

Answer 26

Use "==" for simply checking if two values are equal Use "is" for comparing **identities** (i.e., whether two variables refer to the same object in memory) ## Footnote E.g., a = [1, 2] b = [1, 2] a is b # ❌ False (not the same object) vs a = [1, 2, 3] b = a a is b # ✅ True

Question 27

print([1,2] is [1,2]) What does the above print

Answer 27

False ## Footnote "is" compares **identities** (i.e., whether two variables refer to the same object in memory), not for checking if two values are equal per se. E.g., a = [1, 2] b = a a is b # ✅ True

Question 28

a = [1,2] print(a is [1,2]) What does the above print

Answer 28

False ## Footnote "is" compares **identities** (i.e., whether two variables refer to the same object in memory), not for checking if two values are equal per se. E.g., a = [1, 2] b = a a is b # ✅ True

Question 29

a = [1,2] b = a print(a is b) What does the above print

Answer 29

True ## Footnote "is" compares **identities** (i.e., whether two variables refer to the same object in memory), not for checking if two values are equal per se.

Question 30

a, b = a+1, b+1 a, b += 1 a, b += 1, 1 All of the above appear to do the same thing, but which will actually work

Answer 30

a, b = a+1, b+1 & a, b += 1, 1 work. a, b = a+1, b+1 Is most Pythonic