Practice

Question 1

Remove an item from a list

Answer 1

Answer

Question 2

Reverse list

Answer 2

.reverse() in place, only for list
reversed() returns iterator
(if the input list changes iterator sees it)
[::-1] reversed copy, slow

Question 3

Sequence Functions

Answer 3

len()
min()
max()

Question 4

Functions that return iterator

Answer 4

reversed(), enumerate(), zip(), map(), filter()

Question 5

Generator usage

Answer 5

infinite sequence

Question 6

Map

Answer 6

map(function, iterables)
map object
transformation function
lambda function (don’t use!)

Question 7

Filter

Answer 7

map(function, iterable)
map(None, iterable) True elements
lambda function

Question 8

Generator expression without ()

Answer 8

list(square(x) for x in numbers)

Question 9

Sum

Answer 9

sum(iterable, start)
start = 0
can’t sum strings

Question 10

Zip

Answer 10

zip(iterables)
zip(result_iterable)
dict(zip(fields, values))
strict

Question 11

Enumerate

Answer 11

enumerate(iterable, start=0)

Question 12

Dictionary update()

Answer 12

dict.update(iterable or kwargs)
iterable: dict, iterable of tuples etc.

Question 13

Sort

Answer 13

sort(*, key=None, reverse=False)
list.sort()

Question 14

Max, Min

Answer 14

max(iterable, key, default)
max(arg1, arg2, *args, key)

Question 15

All, Any

Answer 15

all(iterable)
True if iterable is empty

any(iterable)
False if iterable is empty

Question 16

Is Instance

Answer 16

isinstance(object, classinfo)
classinfo - type, class, tuple of types and/or classes

Question 17

Sorted

Answer 17

sorted(iterable, /, *, key=None, reverse=False)
returns a list

Question 18

Dictionary Creation

Answer 18

• dict(dict1)
• dict(iterable of (key, value))
• merge: dict1 | dict2
• merge into a literal: {…, **dict1, …}

Question 19

Is Subclass

Answer 19

issubclass(class, classinfo)
classinfo - class, tuple of classes