📘 Book Presentation

We start with an introduction to Python, its pros and cons, how to use ChatGPT as an aid, and some tips to improve your code.

We also explore what makes code Pythonic. There are many ways to achieve the same result, but some are more Pythonic than others.

# ❌ Not Pythonic
index = 0
for value in l:
    print(index, value)
    index += 1
        

Better like this, it's more Pythonic.

# ✅ Pythonic
for index, value in enumerate(l):
    print(index, value)
        

🧱 Choose Data Types and Structures

We explore the different data types and structures available in Python. Starting with the basics and introducing numpy and pandas. We teach you which is the most suitable for each case.

We also look at curious behaviors like the following. What is the result of the following operation?

print(0.1 + 0.1 + 0.1 - 0.3)
            

🔄 Control with Loops and Conditionals

Control the flow of your program with loops and conditionals. We cover how to use if, elif, else, match, for, while, break, and continue.

Although the ternary operator and walrus are very useful, what will undoubtedly surprise you is the match. An example of its potential.

month = 4
match month:
    case 12 | 1 | 2: print("Winter")
    case 3 | 4 | 5: print("Spring")
    case 6 | 7 | 8: print("Summer")
    case 9 | 10 | 11: print("Fall")
    case _: print("Error")
            

🛠️ Reuse Code with Functions

Discover how to create and use functions to make your code more modular and reusable. We start with the basics and end with pass by value and reference, lambda functions, recursion, decorators, generators, and asynchronous programming.

You'll understand the difference between lists and generators. It's not the same to use "[" as "(".

not_lazy = [i for i in range(1000)] # NOT lazy
is_lazy = (i for i in range(1000)) # IS lazy
            

🧩 Object-Oriented Programming

We continue with object-oriented programming. We see how to create classes and methods, delving into more advanced concepts like duck typing, inheritance, and magic or dunder methods.

Duck typing is both the best and worst of Python. It allows you to do the following, something uncommon in other languages.

class Dog:
    def speak(self):
        print("Woof!")

class Duck:
    def speak(self):
        print("Quack!")

for animal in Dog(), Duck():
    animal.speak()
            

⚠️ Manage Errors with Exceptions

Learn to handle errors and exceptions to make your code more robust. It's very important to manage when things go wrong.

We will also see context managers, something everyone uses but few understand. If you've used "with" to open a file, you've used a context manager. But do you understand it?

with open('file.txt', 'r') as file:
    content = file.read()
            

🧪 Test Your Code

Learn how to write tests to ensure your code works correctly. We will use pytest to test our example program, which detects the position of the International Space Station.

We will also do benchmarking and fuzzing of your code analyzing its coverage. We will learn to make mocks like the following, something useful for testing APIs.

def test_coordinates(response, iss):
    with patch('iss.requests.get') as mock_get:
        mock_get.return_value.json.return_value = response
        mock_get.return_value.raise_for_status = lambda: None
        
        assert iss.above() == True
            

💡 50 Practical Examples

Explore 50 practical examples that will help you apply what you've learned. They cover everything:

• 🤖 Artificial intelligence, neural networks, genetics, and DNA.
• 📊 Dashboards and graphical representation.
• 📈 Financial analysis, betting, statistics, and mathematics.
• 🔐 Encryption, digital signature, quantum computing, prime number factorization, and brute force.
• 🎮 Game development, websites, APIs, and user interfaces.
• 📐 Implementation of simple algorithms.

We will see, for example, how to simulate bets in different scenarios.

import numpy as np

def bet(initial_money, win_prob,
        win_return, lose_return, num_bets):
        
    money = [initial_money]
    p = [win_prob, 1 - win_prob]
    
    for _ in range(num_bets):
        if np.random.choice(['heads', 'tails'], p=p) == 'heads':
            money.append(money[-1] * (1 + win_return))
        else:
            money.append(money[-1] * (1 + lose_return))
            
    return money
            

⚠️ 100 Common Errors

Avoid the most common errors when programming in Python. Besides working, the code must be readable and easy to maintain.

Can you find the problem in the following code?

list = [1, 2, 3, 4, 4, 4, 4, 5]
for x in list:
    if x == 4:
        list.remove(x)
            

Or this one?

names = ['Ana', 'Beatriz', 'Carlos']
ages = [25, 30, 35]
for i in range(len(names)):
    print(f"{names[i]} is {ages[i]} years old")