text: # -*- coding: utf-8 -*-
  """ utilities to convert midi note number to and from note names """
  
  import sys
  from ._aubio import freqtomidi, miditofreq
  
  __all__ = ['note2midi', 'midi2note', 'freq2note', 'note2freq']
  
  py3 = sys.version_info[0] == 3
  if py3:
      str_instances = str
      int_instances = int
  else:
      str_instances = (str, unicode)
      int_instances = (int, long)
  
  
  def note2midi(note):
      """Convert note name to midi note number.
  
      Input string `note` should be composed of one note root
      and one octave, with optionally one modifier in between.
  
      List of valid components:
  
      - note roots: `C`, `D`, `E`, `F`, `G`, `A`, `B`,
      - modifiers: `b`, `#`, as well as unicode characters
        `𝄫`, `♭`, `♮`, `♯` and `𝄪`,
      - octave numbers: `-1` -> `11`.
  
      Parameters
      ----------
      note : str
          note name
  
      Returns
      -------
      int
          corresponding midi note number
  
      Examples
      --------
      >>> aubio.note2midi('C#4')
      61
      >>> aubio.note2midi('B♭5')
      82
  
      Raises
      ------
      TypeError
          If `note` was not a string.
      ValueError
          If an error was found while converting `note`.
  
      See Also
      --------
      midi2note, freqtomidi, miditofreq
      """
      _valid_notenames = {'C': 0, 'D': 2, 'E': 4, 'F': 5, 'G': 7,
                          'A': 9, 'B': 11}
      _valid_modifiers = {
              u'𝄫': -2,                         # double flat
              u'♭': -1, 'b': -1, '\u266d': -1,  # simple flat
              u'♮': 0, '\u266e': 0, None: 0,    # natural
              '#': +1, u'♯': +1, '\u266f': +1,  # sharp
              u'𝄪': +2,                         # double sharp
              }
      _valid_octaves = range(-1, 10)
      if not isinstance(note, str_instances):
          msg = "a string is required, got {:s} ({:s})"
          raise TypeError(msg.format(str(type(note)), repr(note)))
      if len(note) not in range(2, 5):
          msg = "string of 2 to 4 characters expected, got {:d} ({:s})"
          raise ValueError(msg.format(len(note), note))
      notename, modifier, octave = [None] * 3
  
      if len(note) == 4:
          notename, modifier, octave_sign, octave = note
          octave = octave_sign + octave
      elif len(note) == 3:
          notename, modifier, octave = note
          if modifier == '-':
              octave = modifier + octave
              modifier = None
      else:
          notename, octave = note
  
      notename = notename.upper()
      octave = int(octave)
  
      if notename not in _valid_notenames:
          raise ValueError("%s is not a valid note name" % notename)
      if modifier not in _valid_modifiers:
          raise ValueError("%s is not a valid modifier" % modifier)
      if octave not in _valid_octaves:
          raise ValueError("%s is not a valid octave" % octave)
  
      midi = (octave + 1) * 12 + _valid_notenames[notename] \
                               + _valid_modifiers[modifier]
      if midi > 127:
          raise ValueError("%s is outside of the range C-2 to G8" % note)
      return midi
  
  
  def midi2note(midi):
      """Convert midi note number to note name.
  
      Parameters
      ----------
      midi : int [0, 128]
          input midi note number
  
      Returns
      -------
      str
          note name
  
      Examples
      --------
      >>> aubio.midi2note(70)
      'A#4'
      >>> aubio.midi2note(59)
      'B3'
  
      Raises
      ------
      TypeError
          If `midi` was not an integer.
      ValueError
          If `midi` is out of the range `[0, 128]`.
  
      See Also
      --------
      note2midi, miditofreq, freqtomidi
      """
      if not isinstance(midi, int_instances):
          raise TypeError("an integer is required, got %s" % midi)
      if midi not in range(0, 128):
          msg = "an integer between 0 and 127 is excepted, got {:d}"
          raise ValueError(msg.format(midi))
      _valid_notenames = ['C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#',
                          'A', 'A#', 'B']
      return _valid_notenames[midi % 12] + str(int(midi / 12) - 1)
  
  
  def freq2note(freq):
      """Convert frequency in Hz to nearest note name.
  
      Parameters
      ----------
      freq : float [0, 23000[
          input frequency, in Hz
  
      Returns
      -------
      str
          name of the nearest note
  
      Example
      -------
      >>> aubio.freq2note(440)
      'A4'
      >>> aubio.freq2note(220.1)
      'A3'
      """
      nearest_note = int(freqtomidi(freq) + .5)
      return midi2note(nearest_note)
  
  
  def note2freq(note):
      """Convert note name to corresponding frequency, in Hz.
  
      Parameters
      ----------
      note : str
          input note name
  
      Returns
      -------
      freq : float [0, 23000[
          frequency, in Hz
  
      Example
      -------
      >>> aubio.note2freq('A4')
      440
      >>> aubio.note2freq('A3')
      220.1
      """
      midi = note2midi(note)
      return miditofreq(midi)
  