Python

Question 1

Loop through a dict

Answer 1

for key, value in original_dict.items():
reversed_dict[value] = key

Question 2

Filter

Answer 2

adults = filter(myFunc, ages)

Question 3

map

Answer 3

map(function, iterable)

org_list = [1, 2, 3, 4, 5]
# define a function that returns the cube of num

def cube(num):
return num**3

new_list = list(map(cube, org_list))

Question 4

Generators

Answer 4

to print all

def gen_numbers():
for i in range(1, 11):
yield i
for i in gen_numbers():
Print i

to go through them 1 by 1:
numb = gen_numbers()
print(next(numb))

Question 5

While Loop

Answer 5

while i <= n:
print(i)
i = i +

Question 6

for loop

Answer 6

for x in range(0, 3):
print(“We’re on time %d” % (x))

Question 7

Range

Answer 7

range(min, max_not_included, step)
range(6) will produce 0-5
range(1,11) will produce 1-10
range(1,6,2) will produce 1,3
range(10, 0, -1) will produce a countdown

Question 8

Exponent

Answer 8

x**3 (cubed)
x**10

Question 9

Define string that prints when you look at a class

Answer 9

class Elevator:
def __str__(self):
return “Current floor: “ + str(self.current) + “. returned when you call print(elevator) on an instance”

Question 10

Recursion Example

Answer 10

def sum_positive_numbers(n):
# The base case is n being smaller than 1
if n < 1:
return 0
# Recursion Case
return n + sum_positive_numbers(n - 1)

Question 11

Help

Answer 11

help(function_or_class)

Returns doc string

Question 12

Get Values only from a dict

Answer 12

for package in self.packages.values()

Question 13

Random number

Answer 13

import random

random.randint(1,10)

Question 14

Get date

Answer 14

import datetime

bd = datetime.date(20223, 5, 30)
hbd = bd + datetime.timedelta(days=162.5)
hbd.strftime(‘%Y-%m-%d’)

now = datetime.datetime.now()
now.year()

Question 15

Remove an item from a dict

Answer 15

dict.pop(‘key’)

Question 16

Sort lists

Answer 16

list.sort()

new_list = list.sorted()

defaults to alpha, you can specify sort(key=my_sort_function) to determine what sorts.

Question 17

Sets

Answer 17

Set items are unordered, unchangeable, and do not allow duplicate values.

set1 = {‘Python’, ‘R’, ‘SQL’}
set2 = set()
set2.add(‘Python’)

Question 18

Polymorphism

Answer 18

Overwriting parent attribute or function
class Animal:
def age(self):
self.age = 5

class Rabbit(Animal):
def age(self):
self.age = 5

Question 19

Super

Answer 19

class Emp():
    def \_\_init\_\_(self, id, name, Add):
        self.id = id
        self.name = name
        self.Add = Add
 
# Class freelancer inherits EMP
class Freelance(Emp):
    def \_\_init\_\_(self, id, name, Add, Emails):
        super().\_\_init\_\_(id, name, Add)
        self.Emails = Emails
 
Emp_1 = Freelance(103, "Suraj kr gupta", "Noida" , "KKK@gmails")

Question 20

Python

Subprocess Popen

Answer 20

import subprocess

Create a subprocess object
p = subprocess.Popen(["ls", "-l"])

Get the output of the subprocess
output = p.communicate()[0]

Print the output
print(output)

Question 21

Subprocess Run

Answer 21

import subprocess
subprocess.run(["command", "arg1", "arg2"])

Question 22

Python - What does the single underline in front of a variable.

_my_variable = 10

Answer 22

this makes a variable private to the flass or function it’s in.

Question 23

What does the underscore her do

label, has_label, _ = text.partition(‘:’)

Answer 23

The underline is for a returned value you want to throwaway

Question 24

Python

How do you add or combine lists

Answer 24

list1 = [1, 2]
list1.append(3)
list1.extend([5, 6])
list2 = [7,8]
list2 = list2 + [9,10]
list1 += list2
print(list2)

Question 25

# Python what does `3 * [0,0,0]` do?

Answer 25

[0, 0, 0, 0, 0, 0, 0, 0, 0] Nine 0's