Decode DataURL data

def decode(data_url):
    """
    Decode DataURL data
    """
    metadata, data = data_url.rsplit(',', 1)
    _, metadata = metadata.split('data:', 1)
    parts = metadata.split(';')
    if parts[-1] == 'base64':
        data = b64decode(data)
    else:
        data = unquote(data)

    for part in parts:
        if part.startswith("charset="):
            data = data.decode(part[8:])
    return data