Introduction to Text-Based Languages

Programming languages allow us to communicate with computers by giving them specific instructions to follow. In block-based programming (such as Scratch), these instructions are represented as drag-and-drop blocks, but in text-based programming, we write instructions using characters, words, and symbols.

A text-based programming language requires strict adherence to syntax, meaning that the structure, spelling, and punctuation must be exact. Python is one of the most commonly used beginner-friendly text-based languages because of its simple and readable syntax.

Why Learn Text-Based Programming?

Transitioning from block-based coding to text-based programming is essential because:

• Professional Software Development: Most applications and software are built using text-based languages.
• Flexibility & Power: Text-based programming allows for more complex and scalable programs.
• Precision & Control: Unlike block-based languages, text-based programming provides finer control over logic and execution.

Key Differences Between Block-Based and Text-Based Coding

Writing and Running Simple Commands

Setting Up Python

To write and execute Python code, we need an environment to run our programs. This can be:

1. Python IDLE (Integrated Development and Learning Environment) – A built-in editor that comes with Python.
2. Online Python Interpreters – Websites like Replit or Trinket allow running Python code without installation.
3. VS Code / PyCharm – More advanced editors used for professional development.

Hello, World! – Your First Python Program

One of the first things programmers learn is how to display text on the screen. In Python, this is done using the print() function:

print(“Hello, World!”)

Explanation:

• print is a function that tells Python to display something.
• “Hello, World!” is a string, which is a type of data enclosed in quotation marks.
• The parentheses () are necessary to call the function.

Performing Basic Arithmetic in Python

Python can also be used as a calculator. Here are some examples of simple arithmetic operations:

# Addition

print(5 + 3)  # Output: 8

# Subtraction

print(10 – 4)  # Output: 6

# Multiplication

print(6 * 2)  # Output: 12

# Division

print(15 / 3)  # Output: 5.0

# Exponents

print(2 ** 3)  # Output: 8 (2 raised to the power of 3)

Key Takeaways:

• + is used for addition.
• – is used for subtraction.
• * is used for multiplication.
• / is used for division (returns a decimal result).
• ** is used for exponentiation (raising a number to a power).

Importance of Syntax in Text-Based Programming

Python has specific syntax rules that must be followed. If there is a mistake, Python will show an error message instead of running the program.

Common Syntax Errors in Python:

This highlights the precision required when writing text-based code.

Understanding Code Execution in Python

Computers read and execute code line by line in a structured order. For example:

print(“Line 1”)

print(“Line 2”)

print(“Line 3”)

Output:

Line 1

Line 2

Line 3

This structured order is called sequencing, and it is one of the most fundamental concepts in programming.

Using Comments in Code

Comments are lines of text that Python ignores when running the code. They are used to explain what the code does.

# This is a comment

print(“Hello, World!”)  # This prints a message

Why use comments?

• Helps in understanding the code later.
• Useful for debugging.
• Essential in professional coding for team collaboration.

Key Takeaways from 9.1 Syntax Basics

• Python is a text-based language that requires precise syntax.
• The print() function displays text on the screen.
• Python can perform basic arithmetic like addition, subtraction, multiplication, and division.
• Syntax errors occur when rules aren’t followed correctly.
• Code executes line by line in a structured sequence.
• Comments help programmers explain their code without affecting execution.

This foundation is crucial before moving on to more advanced programming concepts in later sections.