MongoDB：使用python，Gridfs将pdf文件存储到Mongo Databse中

Question

需要使用python中的Gridfs在Mongo数据库中存储/导入pdf文件（存在于本地目录中）。 我尝试了一些代码，但无法正常工作。 我尝试过：

public class Weatherapp extends AppCompatActivity {
static TextView ctemp;
static TextView ftemp;
static TextView ktemp;
static TextView location;
static TextView pressure;
static TextView humidity;
static TextView mintempc;
static TextView mintempf;
static TextView mintempk;
static TextView maxtempc;
static TextView maxtempf;
static TextView maxtempk;
static TextView sealevel;
static TextView groundlevel;
static TextView windspeed;
static Button refresh;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_weatherapp);

    LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    Dowlode task = new Dowlode();
    String provider = locationManager.getBestProvider(new Criteria(), false);
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        return;
    }
    Location locationn = locationManager.getLastKnownLocation(provider);
    Double lat = locationn.getLatitude();
    Double lng = locationn.getLongitude();
    task.execute("https://samples.openweathermap.org/data/2.5/weather?lat=35&lon=139&appid=4ba583d5302c8723764443f9d6f08116");
    ctemp = findViewById(R.id.ctemp);
    ftemp = findViewById(R.id.ftemp);
    ktemp = findViewById(R.id.ktemp);
    location = findViewById(R.id.location);
    pressure = findViewById(R.id.pressure);
    humidity = findViewById(R.id.humidity);
    mintempc = findViewById(R.id.mintempc);
    mintempf = findViewById(R.id.mintempf);
    mintempk = findViewById(R.id.mintempk);
    maxtempc = findViewById(R.id.maxtempc);
    maxtempf = findViewById(R.id.maxtempf);
    maxtempk = findViewById(R.id.maxtempk);
    sealevel = findViewById(R.id.sealevel);
    groundlevel = findViewById(R.id.groundlevel);
    windspeed = findViewById(R.id.windspeed);
    refresh = findViewById(R.id.refresh);
}

所以请帮助我解决这些问题。我正在使用Python，gridfs