This is a slightly adapted version of Valhalla's code to decode a polyline

valhalla_decode_polyline.py

def decode_polyline(encoded: str,
                    order: str = "lonlat") -> List[List]:
    """
    Code drawn from https://valhalla.github.io/valhalla/decoding/
    :param order: Coordinate order: 'lonlat' (default) or 'latlon'
    :param encoded: String-encoded polyline
    :return: Decoded polyline as a list of [lat, lon] coordinates
    """
    inv = 1.0 / 1e6
    decoded = []
    previous = [0, 0]
    i = 0
    # for each byte
    while i < len(encoded):
        # for each coord (lat, lon)
        ll = [0, 0]
        for j in [0, 1]:
            shift = 0
            byte = 0x20
            # keep decoding bytes until you have this coord
            while byte >= 0x20:
                byte = ord(encoded[i]) - 63
                i += 1
                ll[j] |= (byte & 0x1f) << shift
                shift += 5
            # get the final value adding the previous offset and remember it for the next
            ll[j] = previous[j] + (~(ll[j] >> 1) if ll[j] & 1 else (ll[j] >> 1))
            previous[j] = ll[j]
        # scale by the precision and chop off long coords also flip the positions so
        # its the far more standard lon,lat instead of lat,lon
        if order == "lonlat":
            decoded.append([float('%.6f' % (ll[1] * inv)), float('%.6f' % (ll[0] * inv))])
        else:
            decoded.append([float('%.6f' % (ll[0] * inv)), float('%.6f' % (ll[1] * inv))])
    # hand back the list of coordinates
    return decoded