小编Kid*_*dus的帖子

所以我在网上看了一些代码,我遇到了一条线(在第286行):
if depth > 0 and best <= -MATE_VALUE is None and nullscore > -MATE_VALUE:

我理解困难的部分是best <= -MATE_VALUE is None.

所以我解雇了翻译,看看如何value1 > value2 is value3工作等陈述.
所以我试过了

>>> 5 > 2 is True
False

>>> (5 > 2) is True 
True

>>> 5 > (2 is True) 
True

我的问题

为什么5 > 2 is True不True呢？这些东西通常如何运作？

谢谢.

将 Firebase Firestore 依赖项添加到我的应用后出现错误。

implementation 'com.google.firebase:firebase-firestore:21.2.1'

添加此依赖项后编译会出现以下错误：

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:mergeExtDexDebug'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade
   > java.lang.OutOfMemoryError (no error message)

和堆栈跟踪：

    at org.gradle.workers.internal.DefaultWorkerExecutor$WorkerExecution.waitForCompletion(DefaultWorkerExecutor.java:285)
    at org.gradle.internal.work.DefaultAsyncWorkTracker.waitForItemsAndGatherFailures(DefaultAsyncWorkTracker.java:115)
    at org.gradle.internal.work.DefaultAsyncWorkTracker.access$000(DefaultAsyncWorkTracker.java:34)
    at org.gradle.internal.work.DefaultAsyncWorkTracker$2.run(DefaultAsyncWorkTracker.java:83)
    at org.gradle.internal.Factories$1.create(Factories.java:25)
    at org.gradle.internal.work.DefaultWorkerLeaseService.withoutLocks(DefaultWorkerLeaseService.java:254)
    at org.gradle.internal.work.DefaultWorkerLeaseService.withoutProjectLock(DefaultWorkerLeaseService.java:165)
    at org.gradle.internal.work.DefaultWorkerLeaseService.withoutProjectLock(DefaultWorkerLeaseService.java:159)
    at org.gradle.internal.work.StopShieldingWorkerLeaseService.withoutProjectLock(StopShieldingWorkerLeaseService.java:90)
    at org.gradle.internal.work.DefaultAsyncWorkTracker.waitForCompletion(DefaultAsyncWorkTracker.java:79)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$5.run(ExecuteActionsTaskExecuter.java:412)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:402)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:394)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:92)
    at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:393)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:376)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.access$200(ExecuteActionsTaskExecuter.java:80)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$TaskExecution.execute(ExecuteActionsTaskExecuter.java:213)
    at …

题:

如何在开始时快速将0添加到大型数组(~600 000个条目)中,以使数组的长度达到下一个2的幂.(2 ^ n)除了np.concatinate()之外还有更快的解决方案吗？

我已经尝试过的:

• 使用np.concatenate(0,arr)函数,直到数组的长度等于2的下一个幂.我的代码有效,只需要很长时间.

这是垫左功能:

def PadLeft(arr):
    nextPower = NextPowerOfTwo(len(arr))
    deficit = int(math.pow(2, nextPower) - len(arr))
    #for x in range(1, int(deficit)):
    for x in range(0, deficit):    
        arr = np.concatenate(([0], arr))
    return arr

这是两个功能的下一个功能:

def NextPowerOfTwo(number):
    # Returns next power of two following 'number'
    return math.ceil(math.log(number,2))

我的实施:

arr = np.ones(())
a = PadLeft(arr)

谢谢!

我是新的android开发人员.

我正在尝试使用此代码从我的网络服务器访问数据....

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

    URL url;
    try {
        url = new URL("http://www.mysite.net/LEDstate.txt");

        HttpURLConnection urlConnection = (HttpURLConnection) url
                .openConnection();

        InputStream in = urlConnection.getInputStream();

        InputStreamReader isw = new InputStreamReader(in);

        int data = isw.read();
        while (data != -1) {
            char current = (char) data;
            data = isw.read();
            //System.out.print(current);


            TextView t = (TextView) findViewById(R.id.ledstate);

            t.setText(current); 
        }
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return …