* @throws NullPointerException if {@code string} is {@code null}
   * @since 14.0
   */
  @GwtIncompatible // regular expressions
  @CheckForNull
  public static Float tryParse(String string) {
    if (Doubles.FLOATING_POINT_PATTERN.matcher(string).matches()) {
      // TODO(lowasser): could be potentially optimized, but only with
      // extensive testing
      try {
        return Float.parseFloat(string);

Activating a virtual environment also changes a couple of other things, but this is one of the most important things it does.

## Checking a Virtual Environment

When you check if a virtual environment is active, for example with:

//// tab | Linux, macOS, Windows Bash

* Log warning about `email-validator` only when used. PR [#946](https://github.com/tiangolo/fastapi/pull/946).
* Simplify [Peewee docs](https://fastapi.tiangolo.com/advanced/sql-databases-peewee/) with double dependency with `yield`. PR [#947](https://github.com/tiangolo/fastapi/pull/947).

       * because their next fields won't change. Statistically, at the default threshold, only
       * about one-sixth of them need cloning when a table doubles. The nodes they replace will be
       * garbage collectable as soon as they are no longer referenced by any reader thread that may
       * be in the midst of traversing table right now.
       */

    val response1 = get(server.url("/a"))
    assertThat(response1.body.string()).isEqualTo("A")
    assertThat(response1.header("Allow")).isNull()
    assertThat((response1.receivedResponseAtMillis - t0).toDouble()).isCloseTo(0.0, 250.0)

    // A conditional cache hit updates the cache.
    Thread.sleep(500) // Make sure t0 and t1 are distinct.
    val t1 = System.currentTimeMillis()

       * because their next fields won't change. Statistically, at the default threshold, only
       * about one-sixth of them need cloning when a table doubles. The nodes they replace will be
       * garbage collectable as soon as they are no longer referenced by any reader thread that may
       * be in the midst of traversing table right now.
       */

C'est le framework Python le plus populaire et il bénéficie d'une grande confiance. Il est utilisé pour construire
des systèmes tel qu'Instagram.

Il est relativement fortement couplé aux bases de données relationnelles (comme MySQL ou PostgreSQL), de sorte qu'il
n'est pas très facile d'utiliser une base de données NoSQL (comme Couchbase, MongoDB, Cassandra, etc.) comme principal moyen de
stockage.

 *       timeout point. Similarly, a SMALL is always discriminable as larger than SHORT and smaller
 *       than MEDIUM. And so on. These constants are set to conservative values, but even so, if
 *       there is ever any doubt, they can all be increased in one spot to rerun tests on slower
 *       platforms.
 *   <li>All threads generated must be joined inside each test case method (or {@code fail} to do

#3498db;\n  --warning: #f39c12;\n  --danger: #e74c3c;\n  --light: #f8f9fa;\n  --dark: #343a40;\n}\n\n.animation__shake {\n  -webkit-animation: shake 1500ms;\n  animation: shake 1500ms;\n}\n\n.animation__wobble {\n  -webkit-animation: wobble 1500ms;\n  animation: wobble 1500ms;\n}\n\n.preloader {\n  display: -ms-flexbox;\n  display: flex;\n  background-color: #f4f6f9;\n  height: 100vh;\n  width: 100%;\n  transition: height 200ms linear;\n  position: fixed;\n  left: 0;\n  top: 0;\n  z-index: 9999;\n}\n\n.dark-mode...

Mais en même temps, les fonctions définies avec `async def` doivent être appelées avec `await` et donc dans des fonctions définies elles aussi avec `async def`.

Vous avez donc remarqué ce paradoxe d'oeuf et de la poule, comment appelle-t-on la première fonction `async` ?