01 - Learn the Basics of Python

• python
• by Sn0wAlice

Introduction

Python is a beginner-friendly programming language known for its readability and simplicity. This step will help you set up Python, understand basic syntax, and write your first Python program.

---

1. Installing Python

Windows/macOS/Linux

• Download Python from the official site: python.org
• Install it and ensure pip (Python package manager) is included.
• Verify installation:

  python --version
  

  or (on some systems)

  python3 --version
  

---

2. Running Python Code

You can run Python code using:

• Interactive Mode (REPL): Open terminal and type python.
• Script Mode: Create a .py file and execute it:

  python script.py
  

---

3. Writing Your First Python Program

Create a file hello.py and add:

print("Hello, Python!")

Run it:

python hello.py

---

4. Understanding Variables & Data Types

Variable Declaration

name = "Alice"
age = 25
is_python_learner = True

Data Types in Python

• String (str): "Hello"
• Integer (int): 25
• Float (float): 3.14
• Boolean (bool): True or False
• List (list): [1, 2, 3]
• Dictionary (dict): {"name": "Alice", "age": 25}

Check data types:

print(type(name))  # Output: <class 'str'>

---

5. Working with Input & Output

Printing Output

print("Welcome to Python!")

Taking User Input

name = input("Enter your name: ")
print("Hello, " + name + "!")

---

6. Operators in Python

Arithmetic Operators

x = 10
y = 5
print(x + y, x - y, x * y, x / y, x % y)

Comparison Operators

print(10 > 5)  # True
print(10 == "10")  # False

---

7. Writing Comments in Python

• Single-line comment:

  # This is a comment
  print("Hello")
  

• Multi-line comment:

  """
  This is a multi-line comment
  describing the code.
  """
  

---

8. Python Indentation

Python uses indentation instead of {}:

if 5 > 2:
    print("Five is greater than two!")

---

Exercises

• Install Python and verify the version.
• Run Python in interactive mode and try printing a message.
• Create a Python script that asks for a user's name and prints a greeting.
• Declare variables of different types and print their types.
• Write a small script using arithmetic operators.

---

Conclusion

You have now set up Python, learned basic syntax, and written your first program. The next step is to dive deeper into control flow with loops and conditionals.

---