Python Program Examples – Simple Code Examples for Beginners

freeCodeCamp

By Shittu Olumide

Mark Twain said that the secret of getting ahead is getting started. Programming can seem daunting for beginners, but the best way to get started is to dive right in and start writing code.

Simple code examples are a great way for beginners to get their feet wet and learn the basics of programming. In this article, I will provide a series of simple code examples that are perfect for Python beginners.

These examples cover a range of programming concepts and will help you develop a solid foundation in programming. Whether you're new to programming or just looking to brush up on your skills, these code examples will help you get started on your coding journey.

If you need to learn some Python basics, I've added some helpful resources at the end of this tutorial.

How to Build a Number Guessing Game in Python

In this project, you will create a simple number guessing game that allows the user to guess a random number between 1 and 100. The program will give hints to the user after each guess, indicating whether their guess was too high or too low, until the user guesses the correct number.

Code:

import random secret_number = random.randint(1, 100) while True: guess = int(input("Guess the number between 1 and 100: ")) if guess == secret_number: print("Congratulations! You guessed the number!") break elif guess < secret_number: print("Too low! Try again.") else: print("Too high! Try again.") 

Explanation:

• Start by importing the random module, which will allow you to generate a random number.
• Generate a random number between 1 and 100 using the randint() function from the random module, and assign it to a variable.
• Create a loop that allows the user to guess the number until they guess correctly. Inside the loop, prompt the user to enter their guess using the input() function, and convert their input to an integer using the int() function.
• Add a conditional statement inside the loop that checks whether the user's guess is correct, too high, or too low. If the guess is correct, print a congratulatory message and break out of the loop. If the guess is too high or too low, print a hint message to help the user guess the number correctly.
• Run the program and play the number guessing game!

How to Build a Simple Password Generator in Python

A password generator, as the name implies, generates a random password of a particular length using different combination of characters, and special characters.

Code:

import random import string def generate_password(length): """This function generates a random password of a given length using a combination of uppercase letters, lowercase letters, digits, and special characters""" # Define a string containing all possible characters all_chars = string.ascii_letters + string.digits + string.punctuation # Generate a password using a random selection of characters password = "".join(random.choice(all_chars) for i in range(length)) return password # Test the function by generating a password of length 10 password = generate_password(10) print(password) 

Explanation:

• We import the random and string modules which we use to generate random values and work with strings, respectively.
• Next, we define a function called generate_password that takes a single parameter length , which specifies the length of the password that needs to be generated.
• Inside the function, we define a string called all_chars which contains all possible characters that can be used to generate the password. We use the string.ascii_letters , string.digits , and string.punctuation constants to create this string.
• We then use list comprehension to generate a list of length random characters from the all_chars string using the random.choice() function. Finally, we join these characters together into a single string using the "".join() function and return the result.
• To test the function, we call it with an argument of 10 to generate a password of length 10 and print the result.

Note that this is a very simple password generator and may not be suitable for use in real-world scenarios where security is a concern.

How to Build a Password Checker in Python

We will build a password checker in this section. Its job is to check if a password is strong enough based on some of the criteria we set. It'll print an error if any of the password criteria isn't met.

Code:

# Define a function to check if the password is strong enough def password_checker(password): # Define the criteria for a strong password min_length = 8 has_uppercase = False has_lowercase = False has_digit = False has_special_char = False special_chars = "!@#$%^&*()-_=+[\|;:',/?" # Check the length of the password if len(password) < min_length: print("Password is too short!") return False # Check if the password contains an uppercase letter, lowercase letter, digit, and special character for char in password: if char.isupper(): has_uppercase = True elif char.islower(): has_lowercase = True elif char.isdigit(): has_digit = True elif char in special_chars: has_special_char = True # Print an error message for each missing criteria if not has_uppercase: print("Password must contain at least one uppercase letter!") return False if not has_lowercase: print("Password must contain at least one lowercase letter!") return False if not has_digit: print("Password must contain at least one digit!") return False if not has_special_char: print("Password must contain at least one special character!") return False # If all criteria are met, print a success message print("Password is strong!") return True # Prompt the user to enter a password and check if it meets the criteria password = input("Enter a password: ") password_checker(password) 

Explanation:

• In this code, we define a function called password_checker() that takes a password as an argument and checks if it meets certain criteria for strength.
• We first define the criteria for a strong password – a minimum length of 8 characters, at least one uppercase letter, one lowercase letter, one digit, and one special character.
• We then check the length of the password and whether it contains the required types of characters using a for loop that iterates through each character in the password.
• If the password fails to meet any of the criteria, we print an error message and return False to indicate that the password is not strong enough. Otherwise, we print a success message and return True .
• Finally, we prompt the user to enter a password using the input() function and pass it to the password_checker() function to check if it meets the criteria.

How to Build a Web Scraper in Python

A web scraper scrapes/gets data from webpages and saves it in any format we want, either .csv or .txt. We will build a simple web scraper in this section using a Python library called Beautiful Soup.

Code:

import requests from bs4 import BeautifulSoup # Set the URL of the webpage you want to scrape url = 'https://www.example.com' # Send an HTTP request to the URL and retrieve the HTML content response = requests.get(url) # Create a BeautifulSoup object that parses the HTML content soup = BeautifulSoup(response.content, 'html.parser') # Find all the links on the webpage links = soup.find_all('a') # Print the text and href attribute of each link for link in links: print(link.get('href'), link.text) 

Explanation:

• In this code, we first import the requests and BeautifulSoup modules which are used to make HTTP requests and parse HTML content, respectively.
• Next, we set the URL of the webpage that we want to scrape in a variable called url .
• We then use the requests.get() function to send an HTTP GET request to the URL and retrieve the HTML content of the webpage as a response.
• We create a BeautifulSoup object called soup that parses the HTML content of the response using the html.parser parser.
• We then use the soup.find_all() method to find all the links on the webpage and store them in a variable called links .
• Finally, we use a for loop to iterate through each link in links and print the text and href attribute of each link using the link.get() method.

How to Build a Currency Converter in Python

A currency converter is a program that helps users convert the value of one currency into another currency. You can use it for a variety of purposes, such as calculating the cost of international purchases, estimating travel expenses, or analyzing financial data.

Note: we will use the ExchangeRate-API to get the exchange rate data, which is a free and open-source API for currency exchange rates. But there are other APIs available that may have different usage limits or requirements.

Code:

# Import the necessary modules import requests # Define a function to convert currencies def currency_converter(amount, from_currency, to_currency): # Set the API endpoint for currency conversion api_endpoint = f"https://api.exchangerate-api.com/v4/latest/ " # Send a GET request to the API endpoint response = requests.get(api_endpoint) # Get the JSON data from the response data = response.json() # Extract the exchange rate for the target currency exchange_rate = data["rates"][to_currency] # Calculate the converted amount converted_amount = amount * exchange_rate # Return the converted amount return converted_amount # Prompt the user to enter the amount, source currency, and target currency amount = float(input("Enter the amount: ")) from_currency = input("Enter the source currency code: ").upper() to_currency = input("Enter the target currency code: ").upper() # Convert the currency and print the result result = currency_converter(amount, from_currency, to_currency) print(f"  is equal to  ") 

Explanation:

• In this code, we define a function called currency_converter() that takes an amount, source currency code, and target currency code as arguments and returns the converted amount.
• We first set the API endpoint for currency conversion using the from_currency parameter and the requests module to send a GET request to the endpoint.
• We then extract the exchange rate for the target currency from the JSON data returned by the API using the to_currency parameter and calculate the converted amount by multiplying the exchange rate with the amount parameter.
• Finally, we prompt the user to enter the amount , from_currency , and to_currency using the input() function and pass them to the currency_converter() function to convert the currency. The converted amount is then printed using string formatting.

Conclusion

All these projects are very simple and easy to build. If you really want to improve your Python skills, I'd advise you to take the code, modify and edit it, and build upon it. You can turn many of these simple projects into much more complex applications if you want.

If you need to learn some Python basics, check out these helpful resources:

• How to build your first Python project – YouTube course
• Python for Everybody – full university course from Dr. Chuck
• Learn Python for beginners – free courses
• freeCodeCamp's Scientific Computing with Python and Data Analysis with Python certifications

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