Exercises with Solutions in Python

Coding exercises and solutions in Python. They can also be seen as code snippets that may be useful for some everyday tasks.

Exercises with Solutions in Python

Exercise 1: Input/output strings

Write a program that reads the user name as an input and outputs a welcome message.

Click here to see a possible solution

user_name = input('Write your first name: ')
print('Welcome,', user_name, '!')
print('Welcome, {}!'.format(user_name))

Exercise 2: Some Boolean string methods

Write a program that reads the user input and outputs the following pieces of information about it:

Does it have only space?
Is it a number?
Is it alphabetic?
Is it alphanumeric?
Is it in uppercase?
Is it in lowercase?
Is it capitalized?

Click here to see a possible solution

user_input = input('Enter something: ')
print('The Python primitive datatype of this value is', type(user_input))
print('Does it have only space?', user_input.isspace())
print('Is it a number?', user_input.isnumeric())
print('Is it alphabetic?', user_input.isalpha())
print('Is it alphanumeric?', user_input.isalnum())
print('Is it in uppercase?', user_input.isupper())
print('Is it in lowercase?', user_input.islower())
print('Is it capitalized?', user_input.istitle())

Exercise 3: Input/output numbers

Write a program that reads the user input number and outputs a message saying its antecedent and successor.

Click here to see a possible solution

user_input = int(input('Enter a number: '))
antecedent = user_input - 1
successor = user_input + 1
print('By analyzing number {}, its antecedent is {} and its successor is {}.'.format(user_input, antecedent, successor))

Exercise 4: Formatting strings

Write a program that reads the user input number and outputs a message saying its double, triple, and square root with at most two decimal digits.

Click here to see a possible solution

user_input = int(input('Enter a number: '))
print(  'The double of {} is {}.'.format(user_input, 2 * user_input)  )
print(  'The triple of {} is {}.'.format(user_input, 3 * user_input)  )
print(  'The square root of {} is {:.2f}.'.format(user_input, user_input ** 0.5)  )

Exercise 5: Computing the average grade

Write a program that receives two student grades and outputs the average grade.

Click here to see a possible solution

grade_1 = float(input('Enter the first grade: '))
grade_2 = float(input('Enter the second grade: '))
print('The first student grade is {}.'.format(grade_1))
print('The second student grade is {}.'.format(grade_2))
print('The average between {} and {} is {}'.format(grade_1, grade_2, (grade_1 + grade_2)/2))

Exercise 6: Distance conversions

Write a program that receives a distance value in meters and outputs a message saying its corresponding values in km, hm, dam, dm, cm, and mm.

Click here to see a possible solution

meter_distance = float(input('Enter the distance in meters: '))
km_distance = meter_distance / 1000
hm_distance = meter_distance / 100
dam_distance = meter_distance / 10
dm_distance = meter_distance * 10
cm_distance = meter_distance * 100
mm_distance = meter_distance * 1000
print('The measure of {} m correspond to \n {} km \n {} hm \n {} dam \n {} dm \n {} cm \n {} mm'.format(meter_distance, km_distance,
                                                                                                        hm_distance, dam_distance, dm_distance, cm_distance, mm_distance))

Exercise 7: Multiplication table

Write a program that receives a number and gives its multiplication table like this:

------------
x 1 = 3
x 2 = 6
x 3 = 9
x 4 = 12
x 5 = 15
x 6 = 18
x 7 = 21
x 8 = 24
x 9 = 27
x 10 = 30
------------

Click here to see a possible solution

user_input_number = int(input('Enter a number to see its multiplication table: '))
print('-' * 12)
print('{} x 1 = {}'.format( user_input_number, user_input_number * 1 ))
print('{} x 2 = {}'.format( user_input_number, user_input_number * 2 ))
print('{} x 3 = {}'.format( user_input_number, user_input_number * 3 ))
print('{} x 4 = {}'.format( user_input_number, user_input_number * 4 ))
print('{} x 5 = {}'.format( user_input_number, user_input_number * 5 ))
print('{} x 6 = {}'.format( user_input_number, user_input_number * 6 ))
print('{} x 7 = {}'.format( user_input_number, user_input_number * 7 ))
print('{} x 8 = {}'.format( user_input_number, user_input_number * 8 ))
print('{} x 9 = {}'.format( user_input_number, user_input_number * 9 ))
print('{} x 10 = {}'.format( user_input_number, user_input_number * 10 ))
print('-' * 12)

Exercise 8: Currency conversion using web scrapping

Write a program that receives an amount in the US dollar from the user and outputs a message saying the respective amount in BRL. Get the currency rate by scraping a website.

Click here to see a possible solution

import requests
from bs4 import BeautifulSoup
URL = "https://www.forbes.com/advisor/money-transfer/currency-converter/usd-brl/"
page = requests.get(URL)
soup = BeautifulSoup(page.content, "html.parser")
html_USD_BRL = soup.find('strong')
value_USD_BRL = float(html_USD_BRL.text.split()[3])
user_dollar = float(input('Enter an amount in the US dollar: '))
print('With $ {} you can buy R$ {}'.format(user_dollar, user_dollar * value_USD_BRL))

Exercise 9: Counting string characters and storing in a dictionary

Write a program which counts and print the numbers of each character in a string input given by the user. The outcome should be a dictionary. For example, for the input ‘abcdefgabc’, the output should be {‘a’:2, ‘c’:2, ‘b’:2, ‘e’:1, ‘d’:1, ‘g’:1, ‘f’:1}

Click here to see a possible solution

user_input = input('Enter a string: ')

count = dict()

for string in user_input:

    count[string] = count.get(string, 0) + 1

print(count)

Exercise 10: Reversing a string

Write a program that asks for a string and outputs the reverse of it.

Click here to see a possible solution

user_input = input('Enter a string: ')

print(user_input[::-1])

Exercise 11: Checking substrings

Write a program which asks for a string, checks if it contains a substring, and outputs a corresponding message.

Click here to see a possible solution

user_input_1 = input('Enter a string: ')
user_input_2 = input('Enter a string: ')

if user_input_2 in user_input_1:

    print('The former string contains the latter as a substring.')

else:

    print('The former string does NOT contain the latter as a substring.')

Exercise 12: Pseudo-random integers and maximum value

Create a list composed of pseudo-random integer numbers and find the maximum value in it.

Click here to see a possible solution

import random

list_variable = []

# appending 10000 pseudo-random numbers (ranging between 0 and 10000000) to a list
for i in range(0,1000):
    list_variable.append(random.randint(0,10000000))

print('The maximum integer of the "list_variable" list is', max(list_variable))

Exercise 13: Pseudo-random integers and index

Create a list composed of pseudo-random integer numbers and find the index of the maximum value in it.

Click here to see a possible solution

import random

list_variable = []

# appending 10000 pseudo-random numbers (ranging between 0 and 10000000) to a list
for i in range(0,1000):
    list_variable.append(random.randint(0,10000000))

print('The index of the maximum integer of the "list_variable" list is', list_variable.index(max(list_variable)))

Exercise 14: Reversing a list

Create a program that reverses a list.

Click here to see a possible solution

list_variable = [1, 2, 3, 4, 5]

reverse_list = list_variable[::-1]

print(reverse_list)

Exercise 15: Sorting a dictionary by value with pseudo-random numbers

Create a dictionary with four keys, each having a pseudo-random integer as its value. Sort the dictionary by value.

Click here to see a possible solution

import random

points = {
    "Mary": random.randint(0, 100000), "John": random.randint(0, 100000),
    "Teresa": random.randint(0, 100000), "Peter": random.randint(0, 100000)
    }

sorted_dict = {
    k: v for k, v in sorted(points.items(), key=lambda item: item[1])
}

print(sorted_dict)

Exercise 16: Checking if a file exists

Create a program that check if a file exists in a directory.

Click here to see a possible solution

import os

if os.path.isfile("file.txt"):
    print("File exists!")
else:
    print("File does not exists!")

Exercise 17: Counting the occurrence of each item in the list

Create a list with pseudo-random numbers. Count the occurrence of each item in the list and store the result in a dictionary.

Click here to see a possible solution

import random

my_list = []

for i in range(0,100):
    my_list.append(random.randint(0,10))

# Create an empty dictionary to store the counts
element_count = {}

# Iterate through the list and count occurrences
for element in my_list:
    if element in element_count:
        element_count[element] += 1
    else:
        element_count[element] = 1

print(element_count)

Exercise 18: Checking if all elements in a list are unique

Create a list with pseudo-random integer numbers. Then, check if all elements in this list are unique or not.

Click here to see a possible solution

import random as rd

my_list = []

for i in range(0,10):
    my_list.append(rd.randint(0,100))

print(my_list)
if len(my_list) == len(set(my_list)):
    print("All elements in this list are unique!")
else:
    print("Not all elements in this list are unique!")

Exercise 19: Removing all occurrences of an item from a list

Create a program that removes all occurrences of an item from a list.

Click here to see a possible solution

my_list = [1, 2, 3, 4, 5, 6, 3, 1]
item = 1
my_new_list = [x for x in my_list if x != item]
print(my_list, "\n", my_new_list)

Exercise 20: Flattening a nested list

Create a program that flattens a nested list.

Click here to see a possible solution

my_list = [[1,2], [3,4], [5,6]]
flattened_list = [x for sublist in my_list for x in sublist]
print(flattened_list)

Exercise 21: Merging two dictionaries

Create a program that merges two dictionaries.

Click here to see a possible solution

dict1 = {'apple': 3, 'banana': 1}
dict2 = {'orange':2, 'pear': 4}
merged_dict = {**dict1, **dict2}
print(merged_dict)

Exercise 22: Removing all whitespace from a string

Create a program that removes all whitespace from a string.

Click here to see a possible solution

my_string = "   hello    world    "
print(my_string)
new_string = "".join(my_string.split())
print(new_string)

Exercise 23: Checking if a string is a palindrome

Palindrome is a word, phrase, or sequence that reads the same backwards as forwards, e.g. madam or nurses run. Write a program that checks if an arbitrary string is a palindrome.

Click here to see a possible solution

my_string =input('Enter a string to check if it is a palindrome: ')
if my_string[::-1] == my_string:
    print(my_string, "is a palindrome.")
else:
    print(my_string, "is not a palindroe.")

Exercise 24: Counting the number of words in a string

Create a program that counts the number of words in a string.

Click here to see a possible solution

sentence = "Today I learnt Python at school."
word_count = len(sentence.split())
print("Word count: ", word_count)