slurp_abc_files.py

def parse_filename(filename):
    tune = collections.defaultdict(list)
    in_header = False

    with open(filename, 'r') as f:
        for line in f:
            line = line.strip()
            if line == '' or line.startswith('%'):
                continue

            if line.startswith('X:'):
                if tune:
                    yield tune
                    tune.clear()
                in_header = True

            if in_header:
                (key, value) = line.split(':', 1)
                if key in header_keys:
                    tune[header_keys[key]].append(value.strip())
                if key == 'K':
                    in_header = False
            else:
                tune['abc'] = line.strip()
        else:
            if tune:
                yield tune


for tune in parse_filename('test.abc'):
    print(json.dumps(tune, sort_keys=True, indent=4))