**Course Title:** Modern Python Programming: Best Practices and Trends **Section Title:** Introduction to Python and Environment Setup **Topic:** Exploring Python's basic syntax: Variables, data types, control structures. ### Variables in Python In Python, a variable is a name given to a value. Variables are used to store and manipulate data in a program. You can think of a variable as a labeled box where you can store a value. **Declaring Variables** In Python, you don't need to declare a variable before using it. Instead, you can assign a value to a variable directly. ``` x = 5 # assigns the value 5 to the variable x y = "Hello, World!" # assigns the string "Hello, World!" to the variable y ``` **Basic Data Types** Python has several built-in data types: 1. **Integers**: Whole numbers, either positive, negative, or zero. * Example: `x = 5` 2. **Floats**: Decimal numbers. * Example: `y = 3.14` 3. **Strings**: Sequences of characters, such as words or sentences. * Example: `name = "John Doe"` 4. **Boolean**: A logical value that can be either True or False. * Example: `is_admin = True` 5. **None**: A special value that represents the absence of a value. * Example: `x = None` **Control Structures** Control structures are used to control the flow of a program's execution. ### Conditional Statements Conditional statements are used to execute different blocks of code based on certain conditions. * **If Statements**: An if statement is used to execute a block of code if a condition is true. ``` x = 5 if x > 10: print("x is greater than 10") else: print("x is less than or equal to 10") ``` * **If-Elif Statements**: An if-elif statement is used to check multiple conditions and execute different blocks of code. ``` x = 5 if x > 10: print("x is greater than 10") elif x == 5: print("x is equal to 5") else: print("x is less than 5") ``` ### Loops Loops are used to execute a block of code repeatedly for a specified number of times. * **For Loops**: A for loop is used to execute a block of code for each item in a sequence. ``` fruits = ["apple", "banana", "cherry"] for fruit in fruits: print(fruit) ``` * **While Loops**: A while loop is used to execute a block of code as long as a certain condition is met. ``` x = 0 while x < 5: print(x) x += 1 ``` **Practical Takeaways** * Use meaningful variable names to make your code more readable. * Use the correct data type for the value you are storing. * Use conditional statements to control the flow of your program. * Use loops to execute code repeatedly. **Real-World Example** You are creating a simple calculator program that allows users to perform basic arithmetic operations. You need to store the user's input and perform the operation based on their choice. ``` num1 = float(input("Enter the first number: ")) num2 = float(input("Enter the second number: ")) operation = input("Enter the operation (+, -, \*, /): ") if operation == "+": result = num1 + num2 elif operation == "-": result = num1 - num2 elif operation == "*": result = num1 * num2 elif operation == "/": if num2 != 0: result = num1 / num2 else: print("Invalid operation") result = None print("Result:", result) ``` **What's Next** In the next topic, we will cover understanding Python’s built-in data types: Lists, tuples, dictionaries, sets. **External Resources** For more information on Python's basic syntax, you can refer to the official Python documentation: [https://docs.python.org/3/](https://docs.python.org/3/). **Leave a Comment or Ask for Help** If you have any questions or need help with this topic, please leave a comment below.