Python Variables and Data Types

In Python, a variable is a container for storing data values. Each value has a specific data type, which determines what kind of operations you can perform on it.

Before we dive into the details, here's a quick summary of the basic data types we'll cover:

Data Type	Description	Example Syntax
int	Whole numbers, without decimals.	age = 25
float	Numbers with a decimal point.	price = 199.99
str	A sequence of characters (text).	name = "Hakim"
list	An ordered and changeable collection.	items = ["apple", 10, True]

Now, let's explore each one with practical examples.

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1. Integer (int)

An integer is a data type for whole numbers, both positive and negative, without any decimal components. They are used for counting things, like age or the number of items.

Practice:

# Storing age in an integer variable
age = 25

# Storing the quantity of stock
stock_quantity = 150

print(f"I am {age} years old.")
print(f"Remaining stock: {stock_quantity} items.")
# Output:
# I am 25 years old.
# Remaining stock: 150 items.

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2. Float (float)

A float (floating-point number) is a data type for numbers that have a decimal component. They are perfect for representing values that require precision, like prices, measurements, or scientific data.

Practice:

# Storing a product price
price = 199.99

# Storing height in meters
height = 1.75

print(f"The price of this item is ${price}.")
print(f"My height is {height} meters.")
# Output:
# The price of this item is $199.99.
# My height is 1.75 meters.

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3. String (str)

A string is a data type for storing text or a sequence of characters. In Python, a string must be enclosed in either single quotes ('...') or double quotes ("...").

Practice:

# Storing a name using double quotes
first_name = "Hakim"

# Storing a city name using single quotes
city = 'Jakarta'

# Concatenating strings to create a greeting
greeting = "Hello, " + first_name + "!"

print(greeting)
print(f"I live in the city of {city}.")
# Output:
# Hello, Hakim!
# I live in the city of Jakarta.

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4. List (list)

A list is a data type used to store a collection of items in a single variable. Lists are ordered (items have a defined order) and mutable (you can change, add, and remove items). A list is defined using square brackets [].

Practice:

# A list containing fruit names (all strings)
fruits = ["apple", "banana", "mango"]

# A list with mixed data types
student_data = [101, "Budi", 95.5]

# Accessing an item in the list (index starts at 0)
first_fruit = fruits[0] # Gets "apple"

print(f"The first fruit in the list is {first_fruit}.")
print(f"Student data: {student_data}")
# Output:
# The first fruit in the list is apple.
# Student data: [101, 'Budi', 95.5]

By understanding and practicing with these four basic data types, you have a strong foundation to start building more complex programs with Python. Happy coding! ✨