Python Basics: Variables, Control Flow, Data Structures, and Object‑Oriented Programming

Python is a high‑level programming language designed for code readability, allowing developers to express ideas with minimal syntax; it is widely used in data science, web development, and machine learning.

Variables are created by simple assignment, for example one = 1, two = 2, some_number = 10000. Python supports integers, booleans, strings, floats, and other data types.

Control flow uses if, elif, and else statements to execute code based on conditions, e.g.

if True:
    print("Hello Python If")
if 2 > 1:
    print("2 is greater than 1")
else:
    print("1 is not greater than 2")

Loops enable repeated execution. A while loop runs while a condition is true:

num = 1
while num <= 10:
    print(num)
    num += 1

. A for loop iterates over a range or a collection, e.g.

for i in range(1, 11):
    print(i)

.

Lists store ordered collections of items. They are created with square brackets, indexed from zero, and can be extended with append.

my_integers = [1, 2, 3, 4, 5]
bookshelf = []
bookshelf.append("The Effective Engineer")
print(bookshelf[0])

Dictionaries hold key‑value pairs. Access values via their keys and iterate over items.

dictionary_tk = {"name": "Leandro", "nickname": "Tk", "nationality": "Brazilian"}
print(dictionary_tk["name"])  # Leandro

Object‑oriented programming defines classes as blueprints. The __init__ method initializes attributes, and methods implement behavior. Example of a simple class with getters and setters using @property:

class Vehicle:
    def __init__(self, wheels, tank, seats, max_speed):
        self.number_of_wheels = wheels
        self.type_of_tank = tank
        self.seating_capacity = seats
        self.maximum_velocity = max_speed
    @property
    def number_of_wheels(self):
        return self._wheels
    @number_of_wheels.setter
    def number_of_wheels(self, value):
        self._wheels = value

Encapsulation hides internal state. Public attributes are accessed directly, while non‑public attributes use a leading underscore and are manipulated through methods.

class Person:
    def __init__(self, first_name, email):
        self.first_name = first_name
        self._email = email
    def email(self):
        return self._email
    def update_email(self, new_email):
        self._email = new_email

Inheritance allows a subclass to reuse and extend a parent class. An ElectricCar can inherit from Car without redefining shared attributes:

class Car:
    def __init__(self, wheels, seats, max_speed):
        self.number_of_wheels = wheels
        self.seating_capacity = seats
        self.maximum_velocity = max_speed

class ElectricCar(Car):
    def __init__(self, wheels, seats, max_speed):
        super().__init__(wheels, seats, max_speed)

The tutorial covers these core Python concepts, providing clear explanations and runnable code snippets to help beginners build a solid foundation in the language.