# Python Types Intro { #python-types-intro }

Python has support for optional "type hints" (also called "type annotations").

These **"type hints"** or annotations are a special syntax that allow declaring the <abbr title="for example: str, int, float, bool">type</abbr> of a variable.

By declaring types for your variables, editors and tools can give you better support.

### About `__name__ == "__main__"` { #about-name-main }

The main purpose of the `__name__ == "__main__"` is to have some code that is executed when your file is called with:

<div class="termy">

```console
$ python myapp.py
```

</div>

but is not called when another file imports it, like in:

```Python
from myapp import app
```

#### More details { #more-details }

For example, you could create a project called `philosophers-stone`, this program depends on another package called **`harry`, using the version `1`**. So, you need to install `harry`.

```mermaid
flowchart LR
    stone(philosophers-stone) -->|requires| harry-1[harry v1]
```

    listener = new MockFutureListener(resultFuture);
  }

  public void testFutureGetBeforeCallback() throws Exception {
    // Verify that get throws a timeout exception before the callback is called.
    assertThrows(TimeoutException.class, () -> resultFuture.get(1L, MILLISECONDS));
  }

  public void testFutureGetThrowsWrappedException() throws Exception {
    inputFuture.setException(EXCEPTION);

   * network include {@code node}.
   *
   * <p>This is equal to the union of {@link #inEdges(Object)} and {@link #outEdges(Object)}.
   *
   * <p>If {@code node} is removed from the network after this method is called, the {@code Set}
   * {@code view} returned by this method will be invalidated, and will throw {@code
   * IllegalStateException} if it is accessed in any way, with the following exceptions:
   *
   * <ul>

     */
    public void healthy() {}

    /**
     * Called when the all of the component services have reached a terminal state, either
     * {@linkplain State#TERMINATED terminated} or {@linkplain State#FAILED failed}.
     */
    public void stopped() {}

    /**
     * Called when a component service has {@linkplain State#FAILED failed}.
     *

     */
    public void healthy() {}

    /**
     * Called when the all of the component services have reached a terminal state, either
     * {@linkplain State#TERMINATED terminated} or {@linkplain State#FAILED failed}.
     */
    public void stopped() {}

    /**
     * Called when a component service has {@linkplain State#FAILED failed}.
     *

Interceptors can be chained. Suppose you have both a compressing interceptor and a checksumming interceptor: you'll need to decide whether data is compressed and then checksummed, or checksummed and then compressed. OkHttp uses lists to track interceptors, and interceptors are called in order.

 *
 * Other exception types cancel the current call:
 *
 *  * For synchronous calls made with [Call.execute], the exception is propagated to the caller.
 *
 *  * For asynchronous calls made with [Call.enqueue], an [IOException] is propagated to the caller
 *    indicating that the call was canceled. The interceptor's exception is delivered to the current

If we want to call asynchronous functions in our tests, our test functions have to be asynchronous. AnyIO provides a neat plugin for this, that allows us to specify that some test functions are to be called asynchronously.

## HTTPX { #httpx }

Even if your **FastAPI** application uses normal `def` functions instead of `async def`, it is still an `async` application underneath.