MIDI note helper

midi_note_helper.py

class Note:
    values = {
        "c": 0,
        "d": 2,
        "e": 4,
        "f": 5,
        "g": 7,
        "a": 9,
        "b": 11
    }

    names = ["C", "Cs", "D", "Ds", "E", "F", "Fs", "G", "Gs", "A", "As", "B"]

    # Takes a note in the form "C#4", "Bb2", "A5", etc. and returns
    # the MIDI note number.
    @classmethod
    def note(cls, str):
        matches = re.match('^([ABCDEFGabcdefg])([b#s]?)([0-9])$', str)

        note = matches.group(1).lower()
        acc = matches.group(2).lower()
        octave = int(matches.group(3))

        shift = 0
        if acc == "b":
            shift -= 1
        elif acc == '#':
            shift += 1
        elif acc == 's':
            shift += 1

        value = ((octave+1) * 12) + cls.values[note] + shift
        return int(value)

    @classmethod
    def notes(cls, note_list):
        return map(cls.note, note_list)