Python Tutorial — Learn Python Step by Step

# Check Python 3 version
python3 --version
# Output: Python 3.10.12 (or similar)

# Check pip
pip3 --version
# If not installed: "pip3: command not found"

# Update package list
sudo apt update

# Install Python 3 and pip
sudo apt install python3 python3-pip python3-venv

# Verify
python3 --version
pip3 --version

# Install a specific version (e.g., 3.12) using deadsnakes PPA
sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt update
sudo apt install python3.12 python3.12-venv python3.12-dev

# Create a project directory
mkdir myproject && cd myproject

# Create virtual environment
python3 -m venv venv

# Activate it
source venv/bin/activate

# Your prompt changes: (venv) user@machine:~/myproject$
# Now install packages into this isolated environment
pip install flask requests pandas

# Deactivate when done
deactivate

#!/usr/bin/env python3
# The shebang line above lets you run the script directly: ./hello.py

import platform

print(f"Hello from {platform.system()} {platform.release()}!")
print(f"Python {platform.python_version()}")
print("Installation complete!")

# Make a Python script executable directly
chmod +x hello.py

# Now you can run without typing python3
./hello.py

# The #!/usr/bin/env python3 shebang tells the OS which interpreter to use