mu-editor 1.0.0b13

Installation

You could run Mu from source. Alternatively, go to the link above, choose the directory for your platform and download the latest build of the editor (HINT: they’re ordered by date).

What?

Mu is a very simple code editor for kids, teachers and beginner programmers. It’s written in Python and works on Windows, OSX, Linux and Raspberry Pi.

Why?

There isn’t a cross platform Python code editor that is:

• Easy to use;

• Accessible to everyone;

• Available on all major platforms;

• Well documented (even for beginners);

• Simply coded;

• Currently maintained; and,

• Thoroughly tested.

Mu addresses these needs.

In the Python world, teachers, students and other beginner programmers are forced to use one of the following options:

• IDLE - the long-in-the-tooth, unmaintained and eccentric editor that comes with Python.

• A third party IDE (integrated development environment) for teaching. If “IDE” sounds complicated, that’s because it is.

• A professional programmer’s editor such as vi or emacs.

Such tools are fiddly, complicated and full of distracting “features”. They are completely inappropriate for teaching and learning ~ complexity impedes a novice programmer’s first steps.

How?

Mu’s outlook is:

• Less is more (remove all unnecessary distractions);

• Keep it simple (so Mu is easy to understand);

• Walk the path of least resistance (Mu should be easy);

• Have fun (learning should be a positive experience).

Our first iteration targets MicroPython on the BBC micro:bit.

The BBC’s micro:bit project is aimed at 11-year old children. It consists of a small and simple programmable device. One option is the remarkable work of Damien George in the form of MicroPython, a full re-implementation of Python 3 for microcontrollers including the BBC micro:bit.

The BBC’s “blessed” solution for programming this device is web-based. However, we have observed that this doesn’t provide the optimum experience for Python:

• It requires you to use a web-browser as a text based code editor.

• You need to download the .hex file to flash onto the device and then drag it to the device’s mount point on the filesystem. A rather clunky multi-part process.

• It doesn’t allow you to connect to the device in order to live code in Python via the REPL.

The Mu editor addresses each of these problems: it is a native application specifically designed as a text based coding environment. It makes it easy to flash your code onto the device (it’s only a click of a button). It has a built in REPL client that automatically connects to the device.

Mu has been adapted from my previous work done with Damien George and Dan Pope on the “Puppy” editor for kids. Mu is an ultra-slimmed down version of Puppy.

The code is simple and monolithic - it’s commented and mostly found in a a few obviously named Python files. This has been done on purpose: we want teachers and kids to take ownership of this project and organising the code in this way aids the first steps required to get involved (everything you need to know is in four obvious files).

In terms of features - it’s a case of less is more:

• Create a new Python script.

• Load an existing Python script.

• Save the existing Python script.

• Flash the device with the current script.

• Connect to the device via the REPL (will only work if a device is connected).

• Zoom in/out.

• Day / night (high contrast) modes.

• Built in help (HTML).

• Quit.

That’s it!

Development

If you only want to use Mu then please ignore this section. If you’d like to contribute to the development of Mu read on…

The source code is hosted on GitHub. Please feel free to fork the repository. Assuming you have Git installed you can download the code from the canonical repository with the following command:

$ git clone https://github.com/mu-editor/mu.git

The instructions below assume that you’re working within a Python virtual environment (aka “venv”). Versions of Python

For this to work you’ll need to have Qt5 and at least Python 3.4 installed.

• On Debian based systems this is covered by installing: python3-pyqt5, python3-pyqt5.qsci and python3-pyqt5.qtserialport.

• On Mac OS, first install PyQT5:

  brew install pyqt5 --with-python3

  Then install QScintilla using the recipe from the mu repository:

  brew install https://raw.githubusercontent.com/mu-editor/mu/master/package/extras/qscintilla2.rb

• On Windows:

  Unless you want to build PyQt5 and its dependencies from scratch (a
  non-trivial task) you'll almost certainly want to use the binaries
  provided by Riverbank who provide the Python bindings for Qt. However,
  they've recently switched from providing binary installers to providing
  binary wheels. But they only provide wheels for the most recent versions
  of Python. In addition, the MSI installer version interacts awkwardly
  with virtual environments so you need to install PyQt5 globally and then
  create the virtual environment with --system-site-packages.
  
  ============== ============ =========
  Python Version PyQt Version Installer
  -------------- ------------ ---------
  3.4            5.6          .msi
  -------------- ------------ ---------
  3.5            5.6          .whl
  -------------- ------------ ---------
  3.5            5.7          .whl
  -------------- ------------ ---------
  3.5            5.8          .whl
  -------------- ------------ ---------
  3.6            5.8          .whl
  ============== ============ =========
  
  If you can, use Python 3.5 or greater and install from within the
  virtualenv using the wheels.

or:

c:\dev\mu> py -3.5 -mvenv .venv35

Ensure you have the correct dependencies for development installed by creating a virtualenv and running:

$ pip install -r requirements.txt

If your setup hasn’t yet included installing PyQt5 (eg because you’re using Python 3.5+ on Windows for which wheels are available from PyPI):

(.venv35) c:\dev\mu> pip install PyQt5 QScintilla

To run the local development version of “mu”, in the root of this repository type:

$ python3 run.py

or:

(.venv35) c:\dev\mu> python run.py

There is a Makefile that helps with most of the common workflows associated with development. Typing “make” on its own will list the options thus:

$ make

There is no default Makefile target right now. Try:

make clean - reset the project and remove auto-generated assets.
make pyflakes - run the PyFlakes code checker.
make pep8 - run the PEP8 style checker.
make test - run the test suite.
make coverage - view a report on test coverage.
make check - run all the checkers and tests.
make docs - run sphinx to create project documentation.

Before contributing code please make sure you’ve read CONTRIBUTING.rst.

Release History