python简单密码程序中的无限循环

Question

如果我在第一次尝试"Access Granted"时正确输入密码，我的程序只会打印"Secret password request : "。如果我在其他尝试中输入正确的密码，让我们说第二或第六，即使我输入正确的密码，它也会重复"Acces Denied, try again : "。任何帮助如何解决这个问题？

my_input = input(str("Secret password request : "))
my_input = my_input.lower()
password = "secret1379"
condition = my_input == password

if condition:
    print("Access granted")

while not condition:
    my_input = input("Acces Denied, try again : ")
    if condition:
        print("Access granted")

Answer 1

仅仅因为您在循环中更改了n3，并不意味着my_input会发生变化。它仍会将旧condition与my_input进行比较，因此您必须重新分配password。

您的代码可以在没有此功能的情况下运行，但您也可以删除循环中的condition = my_input.lower() == password，然后删除if，因为当print("Access granted")变为真时循环结束。

Answer 2

package hushtagstudios.com.towme;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.format.DateFormat;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.RatingBar;
import android.widget.TextView;
import android.widget.Toast;

import com.bumptech.glide.Glide;
import com.directions.route.AbstractRouting;
import com.directions.route.Route;
import com.directions.route.RouteException;
import com.directions.route.Routing;
import com.directions.route.RoutingListener;
import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.LatLngBounds;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.Polyline;
import com.google.android.gms.maps.model.PolylineOptions;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import org.json.JSONException;
import org.json.JSONObject;

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
import java.util.Locale;
import java.util.Map;

public class HistorySingleActivity extends AppCompatActivity implements OnMapReadyCallback, RoutingListener {

    private String rideId, currentUserId, customerId, driverId, userDriverOrCustomer;



    private TextView rideLocation;
    private TextView rideDistance;
    private TextView rideDate;
    private TextView userName;
    private TextView userPhone;

    private ImageView userImage;

    private RatingBar mRatingBar;

    private Button mPay;

    private DatabaseReference historyRideInfoDb;

    private LatLng destinationLatLng, pickupLatLng;
    private String distance;
    private Double ridePrice;
    private Boolean customerPaid = false;

    private GoogleMap mMap;
    private SupportMapFragment mMapFragment;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_history_single);

        polylines = new ArrayList<>();

        rideId = getIntent().getExtras().getString("rideId");

        mMapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
        mMapFragment.getMapAsync(this);


        rideLocation = (TextView) findViewById(R.id.rideLocation);
        rideDistance = (TextView) findViewById(R.id.rideDistance);
        rideDate = (TextView) findViewById(R.id.rideDate);
        userName = (TextView) findViewById(R.id.userName);
        userPhone = (TextView) findViewById(R.id.userPhone);

        userImage = (ImageView) findViewById(R.id.userImage);

        mRatingBar = (RatingBar) findViewById(R.id.ratingBar);

        currentUserId = FirebaseAuth.getInstance().getCurrentUser().getUid();

        historyRideInfoDb = FirebaseDatabase.getInstance().getReference().child("history").child(rideId);
        getRideInformation();
    }

    private void getRideInformation() {

        historyRideInfoDb.addListenerForSingleValueEvent(new ValueEventListener() {
            @SuppressLint("SetTextI18n")
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                if(dataSnapshot.exists()){
                    for (DataSnapshot child:dataSnapshot.getChildren()){
                        if (child.getKey().equals("customer")){
                            customerId = child.getValue().toString();
                            if(!customerId.equals(currentUserId)){
                                userDriverOrCustomer = "Drivers";
                                getUserInformation("Customers", customerId);
                            }
                        }
                        if (child.getKey().equals("driver")){
                            driverId = child.getValue().toString();
                            if(!driverId.equals(currentUserId)){
                                userDriverOrCustomer = "Customers";
                                getUserInformation("Drivers", driverId);
                                displayCustomerRelatedObjects();
                            }
                        }
                        if (child.getKey().equals("timestamp")){
                            rideDate.setText(getDate(Long.valueOf(child.getValue().toString())));
                        }
                        if (child.getKey().equals("rating")){
                            mRatingBar.setRating(Integer.valueOf(child.getValue().toString()));

                        }
                        if (child.getKey().equals("customerPaid")){
                            customerPaid =true;
                        }
                        if (child.getKey().equals("distance")){
                            distance = child.getValue().toString();
                            rideDistance.setText(distance.substring(0, Math.min(distance.length(), 5)) + " km");
                            ridePrice = Double.valueOf(distance) * 0.5;

                        }
                        if (child.getKey().equals("destination")){
                            rideLocation.setText(child.getValue().toString());
                        }
                        if (child.getKey().equals("location")){
                            pickupLatLng = new LatLng(Double.valueOf(child.child("from").child("lat").getValue().toString()), Double.valueOf(child.child("from").child("lng").getValue().toString()));
                            destinationLatLng = new LatLng(Double.valueOf(child.child("to").child("lat").getValue().toString()), Double.valueOf(child.child("to").child("lng").getValue().toString()));
                            if(destinationLatLng != new LatLng(0,0)){
                                getRouteToMarker();
                            }
                        }
                    }
                }
            }
            @Override
            public void onCancelled(DatabaseError databaseError) {
            }
        });

    }

    private void getUserInformation(String otherUserDriverOrCustomer, String otherUserId) {
        DatabaseReference mOtherUserDB = FirebaseDatabase.getInstance().getReference().child("Users").child(otherUserDriverOrCustomer).child(otherUserId);
        mOtherUserDB.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                if(dataSnapshot.exists()){
                    Map<String, Object> map = (Map<String, Object>) dataSnapshot.getValue();
                    if(map.get("name") != null){
                        userName.setText(map.get("name").toString());
                    }
                    if(map.get("phone") != null){
                        userPhone.setText(map.get("phone").toString());
                    }
                    if(map.get("profileImageUrl") != null){
                        Glide.with(getApplication()).load(map.get("profileImageUrl").toString()).into(userImage);
                    }
                }

            }
            @Override
            public void onCancelled(DatabaseError databaseError) {
            }
        });
    }

    private void displayCustomerRelatedObjects() {
        mRatingBar.setVisibility(View.VISIBLE);
        mPay.setVisibility(View.VISIBLE);
        mRatingBar.setOnRatingBarChangeListener(new RatingBar.OnRatingBarChangeListener() {
            @Override
            public void onRatingChanged(RatingBar ratingBar, float rating, boolean fromUser) {
                historyRideInfoDb.child("rating").setValue(rating);
                DatabaseReference mDriverRatingDb = FirebaseDatabase.getInstance().getReference().child("Users").child("Drivers").child(driverId).child("rating");
                mDriverRatingDb.child(rideId).setValue(rating);
            }
        });
        if (customerPaid) {
            mPay.setEnabled(false);
        } else {
            mPay.setEnabled(true);
        }
    }





    private String getDate(Long time) {
        Calendar cal = Calendar.getInstance(Locale.getDefault());
        cal.setTimeInMillis(time*1000);
        String date = DateFormat.format("MM-dd-yyyy hh:mm", cal).toString();
        return date;
    }
    private void getRouteToMarker() {
        Routing routing = new Routing.Builder()
                .travelMode(AbstractRouting.TravelMode.DRIVING)
                .withListener(this)
                .alternativeRoutes(false)
                .waypoints(pickupLatLng, destinationLatLng)
                .build();
        routing.execute();
    }
    @Override
    public void onMapReady(GoogleMap googleMap) {
        private List<Polyline> polylines;
        private static final int[] COLORS = new int[]{R.color.primary_dark_material_light};

    }

    @Override
    public void onRoutingFailure(RouteException e) {
        if(e != null) {
            Toast.makeText(this, "Error: " + e.getMessage(), Toast.LENGTH_LONG).show();
        }else {
            Toast.makeText(this, "Something went wrong, Try again", Toast.LENGTH_SHORT).show();
        }


    }

    @Override
    public void onRoutingStart() {
    }
    @Override
    public void onRoutingSuccess(ArrayList<Route> route, int shortestRouteIndex) {

        LatLngBounds.Builder builder = new LatLngBounds.Builder();
        builder.include(pickupLatLng);
        builder.include(destinationLatLng);
        LatLngBounds bounds = builder.build();

        int width = getResources().getDisplayMetrics().widthPixels;
        int padding = (int) (width*0.2);

        CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngBounds(bounds, padding);

        mMap.animateCamera(cameraUpdate);

        mMap.addMarker(new MarkerOptions().position(pickupLatLng).title("pickup location").icon(BitmapDescriptorFactory.fromResource(R.mipmap.ic_pickup)));
        mMap.addMarker(new MarkerOptions().position(destinationLatLng).title("destination"));

        if(polylines.size()>0) {
            for (Polyline poly : polylines) {
                poly.remove();
            }
        }

        polylines = new ArrayList<>();
        //add route(s) to the map.
        for (int i = 0; i <route.size(); i++) {

            //In case of more than 5 alternative routes
            int colorIndex = i % COLORS.length;

            PolylineOptions polyOptions = new PolylineOptions();
            polyOptions.color(getResources().getColor(COLORS[colorIndex]));
            polyOptions.width(10 + i * 3);
            polyOptions.addAll(route.get(i).getPoints());
            Polyline polyline = mMap.addPolyline(polyOptions);
            polylines.add(polyline);

            Toast.makeText(getApplicationContext(),"Route "+ (i+1) +": distance - "+ route.get(i).getDistanceValue()+": duration - "+ route.get(i).getDurationValue(),Toast.LENGTH_SHORT).show();
        }

    }
    @Override
    public void onRoutingCancelled() {
    }
    private void erasePolylines(){
        for(Polyline line : polylines){
            line.remove();
        }
        polylines.clear();
    }


    @Override
    public void onPointerCaptureChanged(boolean hasCapture) {

    }
}