3.Python Basics: REPL, Scripts, and Syntax
Python is a versatile and beginner-friendly programming language. Understanding its basic components—REPL, scripts, and syntax—is essential for anyone starting their Python journey. This tutorial provides a comprehensive overview of these topics.
What is REPL?
REPL stands for Read-Eval-Print Loop. It is an interactive environment where you can type Python commands and see immediate results. This is useful for quick experiments and learning.
Using REPL
To start REPL, simply open your terminal or command prompt and type:
- python
or
- python3
Once inside REPL, you can type Python statements and press Enter to execute them.
Example:
>>> print(‘Hello, World!’)
Hello, World!
Writing and Running Scripts –>Steps to create and run a script:
- Open a text editor or IDE (like VS Code).
- Write your Python code.
- Save the file with a .py extension (e.g., hello.py).
- Run the script from the terminal:
Writing and Running Scripts –>Steps to create and run a script:
- python hello.py
or
- python3 hello.py
Example script:
print(‘Hello from a script!’)
Python Syntax Overview
Python syntax is designed to be readable and straightforward. Here are some key elements:
Variables and Data Types
x = 10 # integer
name = ‘Alice’ # string
Control Structures
if x > 5:
print(‘x is greater than 5’)
Loops
for i in range(3):
print(i)
Functions
def greet(name):
return f’Hello, {name}’
print(greet(‘Alice’))
Comments
def greet(name):
return f’Hello, {name}’
print(greet(‘Alice’))
# This is a comment
Conclusion
Understanding REPL, scripts, and Python syntax is the foundation for becoming proficient in Python. Practice using REPL for quick tests and writing scripts for more complex tasks.