Brief Tour to μSim

This is a short tutorial to using μSim to create your own simulation. Teaching by example, the tutorial will get you started quickly. It provides an overview of how to best use all tools provided by μSim. If needed, additional information is directly accessible from each section.

If you are already familiar with Python, install usim and head straight to the first section. Otherwise, proceed below for a short introduction to install μSim and launch Python.

Installing μSim

The newest version of μSim is readily available via Python’s package manager. You only need Python 3.5 or newer to get started.

python3 -m pip install usim

This takes care of installing μSim (the usim package) and any dependencies. 1

Interactive or Scripted

You can use μSim both from an interactive Python shell, or a Python script. A shell makes it easier to develop and experiment; a script simplifies reuse and reproducibility. However, you can freely switch between the two as you prefer. The only difference is whether you write code to the shell or a file!

The Shell

Python already ships with a basic interactive shell. It can be launched from a terminal by typing python3. Simply enter the code as desired - but make sure to indent it properly! The shell automatically executes any line that is a completed statement, or asks for more with ...:

$ python3
Python 3.7.0 (default, Sep 14 2018, 16:24:12)
[Clang 9.0.0 (clang-900.0.39.2)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> # insert your code after >>> or ...
>>> from usim import run, time
>>>
>>> print('usim version:', usim.__version__)
usim version: 0.1.0
>>>

There are various advanced shells available that make your life easier. For example, ipython3 offers code completion, help messages and other convenience features. 2

Scripting

Python can directly execute code from files. Simply open a file and write your code inside; any text editor is suitable for small scripts. Note that no code is executed at this time.

# my_script.py
from usim import run, time

print('usim version:', usim.__version__)

To run an existing script from a terminal, execute Python with the path of the script.

$ python3 my_script.py
usim version: 0.1.0

As your simulations become more complex, scripts allow you to re-run and fine-tune your work. Various advanced text editors and IDEs are available to help you write correct and maintainable code.

Let’s get started…

You now have Python and μSim ready to get started. Head over to the next section to write your first simulation.

1

Note that μSim does not require any non-Python dependencies. It is fully compatible and tested with PyPy3 as well, if you need more speed.

2

Install it by executing python3 -m pip install ipython.