for (int i = 1; i < values.length; i++) {
          mean = mean + (values[i] - mean) / (i + 1);
        }
        return mean;
      }
    };

    abstract double mean(double[] values);
  }

  static class MeanAndVariance {
    private final double mean;
    private final double variance;

    MeanAndVariance(double mean, double variance) {
      this.mean = mean;
      this.variance = variance;
    }

```Python hl_lines="1  3  7" title="app/main.py"
{!../../docs_src/bigger_applications/app/main.py!}
```

### 🗄 `APIRouter`

🔜 👥 🗄 🎏 🔁 👈 ✔️ `APIRouter`Ⓜ:

```Python hl_lines="5" title="app/main.py"
{!../../docs_src/bigger_applications/app/main.py!}
```

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

En el archivo `main.py` tienes tu aplicación de **FastAPI**:

{* ../../docs_src/app_testing/main.py *}

### Archivo de prueba

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

Здесь файл `main.py` является "точкой входа" в Ваше приложение и содержит инициализацию Вашего приложения **FastAPI**:


{* ../../docs_src/app_testing/main.py *}

### Файл тестов

    #     (NotRequired - Default Java:'src/main/java' & 'src/main/resources' CSharp:'source')
    #   o sql2EntityOutputDirectory: source output directory from as a relative path from the application directory
    #     (NotRequired - Default Java:'src/main/java' CSharp:'source')
    #
    #; applicationOutsideSqlMap = map:{
    #    ; ../../app1 = map:{
    #        ; sqlDirectory = src/main/resources

        mean += (value - mean) / (index + 1);
      } else {
        mean = calculateNewMeanNonFinite(mean, value);
      }
    }
    return mean;
  }

  /**
   * Returns the <a href="http://en.wikipedia.org/wiki/Arithmetic_mean">arithmetic mean</a> of the
   * values. The count must be non-zero.
   *
   * <p>The definition of the mean is the same as {@link Stats#mean}.
   *

      // in NaN naturally.
      sumOfProductsOfDeltas +=
          values.sumOfProductsOfDeltas()
              + (values.xStats().mean() - xStats.mean())
                  * (values.yStats().mean() - yStats.mean())
                  * values.count();
    }
    yStats.addAll(values.yStats());
  }

  /** Returns an immutable snapshot of the current statistics. */

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

📁 `main.py` 👆 ✔️ 👆 **FastAPI** 📱:


{* ../../docs_src/app_testing/main.py *}

### 🔬 📁

⤴️ 👆 💪 ✔️ 📁 `test_main.py` ⏮️ 👆 💯. ⚫️ 💪 🖖 🔛 🎏 🐍 📦 (🎏 📁 ⏮️ `__init__.py` 📁):

``` hl_lines="5"
.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

      count++;
      if (isFinite(value) && isFinite(mean)) {
        // Art of Computer Programming vol. 2, Knuth, 4.2.2, (15) and (16)
        double delta = value - mean;
        mean += delta / count;
        sumOfSquaresOfDeltas += delta * (value - mean);
      } else {
        mean = calculateNewMeanNonFinite(mean, value);
        sumOfSquaresOfDeltas = NaN;
      }
      min = Math.min(min, value);
      max = Math.max(max, value);
    }

private fun mainFiles(): List<File> {
  val directories =
    listOf(
      "$prefix/samples/guide/src/main/java/okhttp3/guide",
      "$prefix/samples/guide/src/main/java/okhttp3/recipes",
      "$prefix/samples/guide/src/main/java/okhttp3/recipes/kt",
    ).map { File(it) }

  return directories.flatMap {
    it
      .listFiles()
      .orEmpty()