msdparser

A comprehensive, pure-Python, speed-optimized MSD parser. MSD is the underlying file format for the SM and SSC simfile formats used by StepMania, as well as a few older formats like DWI.

Full documentation can be found on Read the Docs.

Features

• MSD lexer and parser
• Optional escape sequences (on by default)
• Optional strict parsing (off by default)
• Bidirectionally-lossless parsing & serialization (in most cases)

Installation

msdparser is available on PyPI:

pip install msdparser

Quickstart

parse_msd takes a named file or string argument and yields MSDParameter instances:

>>> msd_data = """
... #VERSION:0.83;
... #TITLE:Springtime;
... #SUBTITLE:;
... #ARTIST:Kommisar;
... """
>>> from msdparser import parse_msd
>>> for param in parse_msd(string=msd_data):
...         print(
...             "key=" + repr(param.key),
...             "value=" + repr(param.value),
...         )
...
key='VERSION' value='0.83'
key='TITLE' value='Springtime'
key='SUBTITLE' value=''
key='ARTIST' value='Kommisar'

MSDParameter instances stringify back to MSD. They can be created from a sequence of strings, typically the key and value:

>>> from msdparser import MSDParameter
>>> pairs = [('TITLE', 'Springtime'), ('ARTIST', 'Kommisar')]
>>> for key, value in pairs:
...     print(str(MSDParameter([key, value])))
...
#TITLE:Springtime;
#ARTIST:Kommisar;

Parameters can be stringified exactly how they were parsed by calling serialize or stringify with exact=True:

>>> import codecs
>>> import filecmp
>>> from msdparser import MSDParameter, parse_msd
>>> with codecs.open("tests/testdata/backup.ssc", encoding="utf-8") as infile:
...     params = list(parse_msd(file=infile))
...
>>> with codecs.open("output.ssc", "w", encoding="utf-8") as outfile:
...     for param in params:
...         param.serialize(outfile, exact=True)
...
>>> filecmp.compare("tests/testdata/backup.ssc", "output.ssc")
True

Developing

msdparser uses rye for package management. Create the virtual environment:

rye sync

Run the unit tests:

rye test

Build the documentation:

./.venv/Scripts/activate
docs/make html