draw_pitch.py

import sys

def hira_to_mora(hira):
    """ Example:
            in:  'しゅんかしゅうとう'
            out: ['しゅ', 'ん', 'か', 'しゅ', 'う', 'と', 'う']
    """

    mora_arr = []
    combiners = ['ゃ', 'ゅ', 'ょ', 'ぁ', 'ぃ', 'ぅ', 'ぇ', 'ぉ',
                 'ャ', 'ュ', 'ョ', 'ァ', 'ィ', 'ゥ', 'ェ', 'ォ']

    i = 0
    while i < len(hira):
        if i+1<len(hira) and hira[i+1] in combiners:
            mora_arr.append('{}{}'.format(hira[i], hira[i+1]))
            i += 2
        else:
            mora_arr.append(hira[i])
            i += 1
    return mora_arr

def circle(x, y, o=False):
    r = ('<circle r="5" cx="{}" cy="{}" style="opacity:1;fill:#000;" />'
        ).format(x, y)
    if o:
        r += ('<circle r="3.25" cx="{}" cy="{}" style="opacity:1;fill:#fff;"'
              '/>').format(x, y)
    return r

def text(x, mora):
    # letter positioning tested with Noto Sans CJK JP
    if len(mora) == 1:
        return ('<text x="{}" y="67.5" style="font-size:20px;font-family:sans-'
                'serif;fill:#000;">{}</text>').format(x, mora)
    else:
        return ('<text x="{}" y="67.5" style="font-size:20px;font-family:sans-'
                'serif;fill:#000;">{}</text><text x="{}" y="67.5" style="font-'
                'size:14px;font-family:sans-serif;fill:#000;">{}</text>'
               ).format(x-5, mora[0], x+12, mora[1])

def path(x, y, typ, step_width):
    if typ == 's':  # straight
        delta = '{},0'.format(step_width)
    elif typ == 'u':  # up
        delta = '{},-25'.format(step_width)
    elif typ == 'd':  # down
        delta = '{},25'.format(step_width)
    return ('<path d="m {},{} {}" style="fill:none;stroke:#000;stroke-width'
            ':1.5;" />').format(x, y, delta)

def pitch_svg(word, patt, silent=False):
    """ Draw pitch accent patterns in SVG

        Examples:
            はし HLL (箸)
            はし LHL (橋)
            はし LHH (端)
    """

    mora = hira_to_mora(word)

    if len(patt) - len(mora) != 1 and not silent:
        print(('pattern should be number of morae + 1 (got: {}, {})'
              ).format(word, patt))
    positions = max(len(mora), len(patt))
    step_width = 35
    margin_lr = 16
    svg_width = max(0, ((positions-1) * step_width) + (margin_lr*2))

    svg = ('<svg class="pitch" width="{0}px" height="75px" viewBox="0 0 {0} 75'
           '">').format(svg_width)

    chars = ''
    for pos, mor in enumerate(mora):
        x_center = margin_lr + (pos * step_width)
        chars += text(x_center-11, mor)

    circles = ''
    paths = ''
    for pos, accent in enumerate(patt):
        x_center = margin_lr + (pos * step_width)
        if accent in ['H', 'h', '1', '2']:
            y_center = 5
        elif accent in ['L', 'l', '0']:
            y_center = 30
        circles += circle(x_center, y_center, pos>=len(mora))
        if pos > 0:
            if prev_center[1] == y_center:
                path_typ = 's'
            elif prev_center[1] < y_center:
                path_typ = 'd'
            elif prev_center[1] > y_center:
                path_typ = 'u'
            paths += path(prev_center[0], prev_center[1], path_typ, step_width)
        prev_center = (x_center, y_center)

    svg += chars
    svg += paths
    svg += circles
    svg += '</svg>'

    return svg

if __name__ == '__main__':
    if len(sys.argv) != 3:
        print('usage: python3 draw_pitch.py <word> <patt>')
        sys.exit()
    print(pitch_svg(sys.argv[1], sys.argv[2], silent=True))