Python Real Python Interview

Question 1

What can you use on a list instad of range to produce keys and values?

Answer 1

Show example of enumerate with fizzbuzz

Question 2

Show an example of list comprehensions vs map and filter on a list [4, 2, 1, 6, 9, 7] to produce the sq and to show if odd

Question 3

Show the difference between sort and sorted and show sorted features

Answer 3

reverse and key

Question 4

Describe the features of sets

Answer 4

unordered and unique

Question 5

demonstrate the use of sets with the list of random words

Question 6

show how generators are better than list comprehensions for very large sequences. Use the sum of square roots example with 1000 integers.

Show a basic example of a generatior expression for a short range

Answer 6

Show a basic example of a generatior expression for a short range
using (), next, show StopIetration

Question 7

Show a better example of checking if a key exists in a dict and returning a default value if not

Answer 7

show an example of .get

Question 8

Show a better example of setting a key in a dict if it doesn’t already exist

Answer 8

show an example of .setdefault

Question 9

Show an example of using default dict to create a dictionary based on the following list :
grades = [
… (‘elliot’, 91),
… (‘neelam’, 98),
… (‘bianca’, 81),
… (‘elliot’, 88),
… ]

Question 10

Create a function that returns the top three most frequent letters given a string. e.g.

top_three_letters(“aabbccc”)
[(‘c’,3), (‘b’,2) (‘a’,1)]
top_three_letters(“aabbccd”)
[(‘a’,2), (‘b’,2) (‘c’,2)]

Show a long winded example and an example using collections

Question 11

What are other names for de-queue

Answer 11

Deque (desk), double-ended queue

Question 12

list the common pythoon data structures and operations on them, what are the times of the operations, e.g., constant time

Answer 12

https://realpython.com/python-data-structures/
The above looks very good

list, pop, append, insert
dequeue appendleft, popleft, append, constant time

Question 13

Show an example of named tuples vs standard tuples and classes

Question 14

show how to time operations

Answer 14

use %timeit in iPython

e.g., %timeit is_upper(‘Hello WORLD”)
from timeit import timeit

Question 15

what is a good data structure to use for checking membership with an example

Answer 15

use sets

Question 16

What is a good operation for checking if all values are the same?

Question 17

What does the itertools module allow you to do?

Answer 17

itertools.repeat
itertools.cycle
itertools.permutations
itertools.combinations

Question 18

Give an example of itertools usage

Answer 18

itertools.repeat example
itertools.cycle examples
itertools.permutations examples
itertools.combinations examples

Question 19

what is the property decorator?

Answer 19

https://www.freecodecamp.org/news/python-property-decorator/

@property can be considered the “pythonic” way of defining getters, setters, and deleters.
By defining properties, you can change the internal implementation of a class without affecting the program, so you can add getters, setters, and deleters that act as intermediaries “behind the scenes” to avoid accessing or modifying the data directly.

Question 20

Describe the functools module

Answer 20

You can use the cached_property decorator to avoid having to process the same information repeatedly (providing the returned data doesn’t change)

Question 21

what are the two functools cache decorators that you can use and what are the differences?

Answer 21

@cached_property and @lru_cache