Python Fundamentals || Arrays, Classes & Objects, For & While Loops, Functions, If else, Inheritance, Lambda.

It's Day #9 of #100daysofMiva. See GitHub for code snippets.

Today, I delved deep into Python, focusing on some fundamental concepts that are crucial for any beginner. This documentation is crafted for those who are just starting their Python journey and want to grasp the basics with practical examples.

If you're a beginner and this is your first time reading this, consider reading

• Day #1 (Part 1) || revisiting Python from scratch
• Day #2 of #100daysofMiva || Python Lists
• Python Tuples, Sets & Dictionaries || Day #5 of #100daysofMiva

This will help you in your learning journey with the fundamentals of Python.

1. Python if-else Statements

The if-else statement is the backbone of decision-making in Python. It allows you to execute certain blocks of code based on a condition.

Syntax:

python

if condition:
    # code block
else:
    # code block

Example:

python

age = 18
if age >= 18:
    print("You are eligible to vote.")
else:
    print("You are not eligible to vote.")

In this example, if the variable age is 18 or more, the program prints that the user is eligible to vote; otherwise, it says they are not eligible.

2. Python while Loops

A while loop repeatedly executes a block of code as long as a specified condition is true.

Syntax:

python

while condition:
    # code block

Example:

python

counter = 0
while counter < 5:
    print("Counter is at:", counter)
    counter += 1

Here, the loop runs until counter reaches 5, incrementing the counter by 1 on each iteration.

3. Python for Loops

for loops are used to iterate over sequences (like lists, tuples, or strings) and execute a block of code for each item.

Syntax:

python

for item in sequence:
    # code block

Example:

python

numbers = [1, 2, 3, 4, 5]
for num in numbers:
    print(num)

This loop iterates over each number in the numbers list and prints it.

4. Python Functions

Functions are blocks of reusable code that perform a specific task. They make your code modular and easier to manage.

Syntax:

python

def function_name(parameters):
    # code block
    return value

Example:

python

def greet(name):
    return f"Hello, {name}!"

message = greet("Miva")
print(message)

This function greet takes a name as a parameter and returns a greeting message.

5. Lambda Functions

A lambda function is a small anonymous function defined with the lambda keyword. It's useful for simple operations that are used only once or for passing into other functions.

Syntax:

python

lambda arguments: expression

Example:

python

multiply = lambda x, y: x * y
result = multiply(2, 3)
print(result)

Here, the lambda function multiplies two numbers and returns the result.

6. Python Arrays (Lists)

Arrays (in Python, they are typically lists) are used to store multiple items in a single variable.

Syntax:

python

list_name = [item1, item2, item3]

Example:

python

fruits = ["apple", "banana", "cherry"]
print(fruits[1])  # Outputs: banana

Lists are indexed starting from 0, so fruits[1] returns the second item, "banana".

7. Python Classes and Objects

Classes and objects are the foundation of Object-Oriented Programming (OOP) in Python. A class is a blueprint for creating objects (instances), and an object is an instance of a class.

Syntax:

python

class ClassName:
    def __init__(self, attribute):
        self.attribute = attribute

Example:

python

class Dog:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def bark(self):
        return f"{self.name} says Woof!"

my_dog = Dog("Rex", 5)
print(my_dog.bark())

In this example, Dog is a class with attributes name and age, and a method bark. The my_dog object is an instance of the Dog class.

8. Python Inheritance

Inheritance allows a new class to inherit attributes and methods from an existing class. This promotes code reuse and can be very powerful when used correctly.

Syntax:

python

class ParentClass:
    # code block

class ChildClass(ParentClass):
    # code block

Example:

python

class Animal:
    def __init__(self, name):
        self.name = name

    def make_sound(self):
        return f"{self.name} makes a sound."

class Cat(Animal):
    def make_sound(self):
        return f"{self.name} says Meow!"

my_cat = Cat("Whiskers")
print(my_cat.make_sound())

Here, Cat inherits from Animal but overrides the make_sound method to return a specific sound for cats.

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