Module music_df.utils.spelling

Functions

def line_of_fifths_to_spelling(i, sharp_char='#', flat_char='b')

Expand source code

def line_of_fifths_to_spelling(i, sharp_char="#", flat_char="b"):
    """Convert from a "fifth-class" (where F is 0) to a spelling.

    >>> line_of_fifths_to_spelling(0)
    'F'
    >>> line_of_fifths_to_spelling(14)
    'F##'
    >>> line_of_fifths_to_spelling(-13)
    'Cbb'
    """
    sharps, letter = divmod(i, 7)
    if sharps >= 0:
        return ALPHABET[letter] + sharp_char * sharps
    return ALPHABET[letter] + flat_char * (-sharps)

Convert from a "fifth-class" (where F is 0) to a spelling.

>>> line_of_fifths_to_spelling(0)
'F'
>>> line_of_fifths_to_spelling(14)
'F##'
>>> line_of_fifths_to_spelling(-13)
'Cbb'

def spelling_to_line_of_fifths(spelling, sharp_char='#', flat_char='b')

Expand source code

def spelling_to_line_of_fifths(spelling, sharp_char="#", flat_char="b"):
    """Convert from a spelling to a "fifth-class" where F is 0.

    >>> spelling_to_line_of_fifths("C")
    1
    >>> spelling_to_line_of_fifths("C#")
    8
    >>> spelling_to_line_of_fifths("C##")
    15
    >>> spelling_to_line_of_fifths("Fbbb")
    -21
    """
    letter = ALPHABET.index(spelling[0])
    sharps = spelling.count(sharp_char)
    flats = spelling.count(flat_char)
    return letter + 7 * sharps + -7 * flats

Convert from a spelling to a "fifth-class" where F is 0.

>>> spelling_to_line_of_fifths("C")
1
>>> spelling_to_line_of_fifths("C#")
8
>>> spelling_to_line_of_fifths("C##")
15
>>> spelling_to_line_of_fifths("Fbbb")
-21