The Editor

The Python editor is perfect for those who want to push their coding skills further. A selection of snippets and a range of pre-made images and music give you a helping hand with your code. The editor is powered by the global Python Community.

The main menu of the editor contains various buttons that allow you to interact with the editor and the micro:bit device. If you have additional features enabled in the editor, for example WebUSB you may see extra buttons availble in this menu.

A picture of the buttons along the top of the editor.

As well as using a mouse, you can use the TAB key to navigate through the options and Enter to activate them. If you're in the text window, The ESC key will re-focus on the menu.

Click on the "Download" button to save a special "hex" file on computer. Plug in BBC micro:bit (it'll show up as USB storage) and drag the newly saved file onto the device. Code will run (or you'll see an error message scroll past on the device's display). See below for how to extract code from a hex file back into the editor.
Click on the "Save" button to save the code onto your computer. Because you're downloading Python code computer might check you want to save the file. It's trying to protect you from downloading random software from the internet. But since this is own code you're safe to proceed. See below for how to load code back into the editor.
It's very easy to load files from computer into the editor: click the load button then drag the file from computer onto the grey "drop" area. Alternatively, you could use the file picker (just click on the link at the bottom to toggle between the two options). The editor knows how to read Python files (whose name ends with ".py") and extract Python code from hex files (whose name ends with ".hex").
This is an experimental feature. It may change in the future and could contain bugs. Clicking the "Blockly" button displays a set of drag-and-drop blocks that can be used to quickly create Python code. Move the blocks, watch Python code appear and change. Moving such blocks will re-write Python code and you may lose work. Furthermore, the arrangement of blocks is currently not saved, just the resulting Python code.
Clicking on the "Snippets" button brings up a menu of Python short-cuts (snippets). Code snippets are short blocks of code to re-use in your own programs. There are snippets for most common things you'll want to do with Python. Select the one you want and fill in the gaps in the code editor to make it do what you want. Snippets are disabled when blockly is enabled.
Clicking on the "Help" button gets you here. But you knew that already, right..? :-) Notice that editor is still available but in a separate tab in browser.
Clicking on the "Share" button creates a unique link that points to script. Add this link to bookmarks to retrieve code. If you share this link others will be able to see code. So code remains private you must set a password and an optional password hint for it. This button is not available if you're running the editor from a local file system.
Everyone likes to show off their awesome Python skills. These buttons are especially useful to zoom-in and zoom-out when you're trying to show code to a large group of people via a projector.

The name and description for your script is shown on the top right hand side. Click them to edit them.

Text window

The other part of the editor is the text window, where we edit our scripts.

A picture of the text area in the code editor.

The editor tries to help out by colouring the text to show what all the different parts of program are. For example, Python keywords (words built into the Python language) are grey. The brighter coloured words are bits of the program you have created. Brown words are constant values that never change and purple words represent strings of characters to display. All the lines are numbered with the current line highlighted.

Hello, World!

A 'Hello, World!' program is traditionally used as a quick test to see if we've got our software or hardware configured correctly.

Here's how we do this in the Python editor:

from microbit import *

display.scroll("Hello, World!")

The first line (from microbit import *) tells MicroPython to get all the bits of Python needed to program the micro:bit.

The second line (display.scroll("Hello, World!")) tells MicroPython to use one of those bits of Python (the display module) to scroll the text, "Hello, World!" across the physical display on the front of the device.

An animation of 'hello world' scrolling over the display.

When you load the Python editor in your browser, this is the default script you will see, asking the micro:bit to scroll the words across the LED screen and then display an image of a heart.

Why not try making the micro:bit scroll your name?


Use blockly to make new Python code from easy to assemble blocks of code.

An animation demonstrating how to use snippets.

Blockly updates Python in the code editor as you move blocks around. There are lots of different blocks to cover all the features of the micro:bit. You can make more advanced code by combining blocks together (such as in the example above).

You should use Blockly to create new code since moving blocks around will overwrite any existing code you have in the editor (and you may lose work as a result). The arrangement of blocks isn't (currently) saved, so Blockly makes a great way to make simple Python code without lots of typing. In the end, you'll learn that simply typing Python is by far the quickest and easiest way to write code.

Not all the features of the micro:bit or MicroPython are available via Blockly. We've done this on purpose. Some of the more advanced and interesting stuff is only available in pure Python.

However, by using Blockly you'll very quickly get the hang of how Python code works and fits together.


Snippets are a cool way to avoid typing. The animation below shows you how to use them:

An animation demonstrating how to use snippets.

You can access snippets from the "Snippets" button (see above), but it's a lot quicker and easier to learn the triggers for the different fragments of code, hit the TAB key to expand the snippet and then fill in the remaining blocks of code so it does what you want.

When blockly is enabled the "Snippets" button is disabled. This avoids snippets from interfering with code that blockly may be generating.

Bug Fixes

Things will go wrong!

You have to imagine Python is the most strict language teacher in the universe... yes, even more strict than that really strict one you have at school. Put simply, you have to type Python without any mistakes for it to work.

All programmers make mistakes and create bugs. It's a fact of life. When you have a bug MicroPython tries to help you out: it will scroll a message on its display. It may even include a line number.

Common bugs include Syntax Errors (which means you've typed it in wrong) and Name Errors (that mean you've typed in correct Python, but it can't work out what you're coding about).

If you're unsure what to do go read the MicroPython docs or open a support request with the micro:bit team.

Further Information


The version of Python that runs on the BBC micro:bit is called MicroPython. It's exactly like real Python except it's designed to run on small devices like the BBC micro:bit. You can find out more about it on the MicroPython site and by reading the MicroPython for micro:bit reference.

How the editor works

To see how the editor actually works? It's easy, to view the "source code" press CTRL-U (or CMD-U on a Mac). There's a secret message for you in the code. Can you find it?

The code for the editor lives in a repository on Github. Github makes it easy to raise a bug report and contribute to the project. For example, here's the HTML code for this help page.

What next?

Python makes it simple to write powerful programs. Can you work out what this program does?

# Press button A for a fortune cookie.
from microbit import *
import random

fortunes = [
    "Never step off a moving bus",
    "This sentence is false",
    "The meaning of life is overrated",
    "Do not touch!",
    "You will receive some advice",
    "My hovercraft is full of eels",

while True:
    if button_a.is_pressed():
        cookie = random.choice(fortunes)

How could you improve it? What changes could you make?