IDLE (the built-in editor for Python) comes automatically with the official Python installer from python.org. Please follow the instructions for your computer:
Go to the download page
👉 https://www.python.org/downloads/
Click the big yellow button for the latest Python 3.x (Windows installer 64-bit).
Run the installer
A window will pop up with options.
✅ Check the box “Add Python to PATH” at the bottom (very important!).
Click Install Now.
Finish installation
Wait for it to complete, then click Close.
You’ll now have a folder in your Start Menu called Python 3.x, which includes IDLE.
Test your installation
Open Command Prompt.
Type:
(or python3 --version if python doesn’t work).
You should see something like: Python 3.12.5.
Launch IDLE
Go to Start → Python 3.x → IDLE (Python 3.x 64-bit).
A window with >>> will open. You can now type Python commands!
Go to the download page
👉 https://www.python.org/downloads/
Download the macOS 64-bit universal2 installer (works for Intel and Apple Silicon/M1/M2).
Run the installer
Open the .pkg file from your Downloads folder.
Follow the prompts (you may need to enter your Mac password).
Security note
If you see “installer can’t be opened because it is from an unidentified developer”:
Go to System Settings → Privacy & Security.
Find the message about Python and click Open Anyway.
Finish installation
Python will be installed in /usr/local/bin/python3.
IDLE will be added to your Applications → Python 3.x folder.
Test your installation
Open Terminal (Applications → Utilities → Terminal).
Type:
You should see something like: Python 3.12.5.
Launch IDLE
Go to Applications → Python 3.x → IDLE.
A window with >>> will open. You can now type Python commands!
If IDLE won’t start: Restart your computer and try again.
If Terminal/Command Prompt says “command not found”:
On Windows, you probably forgot “Add Python to PATH.” Reinstall with that option.
On Mac, open a new Terminal window or log out/in.
Always use python3 on Mac to avoid confusion with the old system Python.