```

</div>

It is **HIGHLY encouraged** that you write or copy the code, edit it and run it locally.

Using it in your editor is what really shows you the benefits of FastAPI, seeing how little code you have to write, all the type checks, autocompletion, etc.

---

## Install FastAPI { #install-fastapi }

The first step is to install FastAPI.

  static final int SAMPLE_MASK = 0xFF;

  /**
   * Compute arrays of valid unicode text, and store it in 3 forms: byte arrays, Strings, and
   * StringBuilders (in a CharSequence[] to make it a little harder for the JVM).
   */
  @BeforeExperiment
  void setUp() {
    long seed = 99;
    Random rnd = new Random(seed);
    strings = new String[SAMPLES];
    for (int i = 0; i < SAMPLES; i++) {

   * Visited Nodes = {N1, N2, N3}
   * EndpointPair [N4, N4] - return
   * Visited Nodes = {N1, N2, N3, N4}
   * </pre>
   */
  private static final class Undirected<N> extends EndpointPairIterator<N> {
    // It's a little weird that we add `null` to this set, but it makes for slightly simpler code.
    private @Nullable Set<@Nullable N> visitedNodes;

    private Undirected(BaseGraph<N> graph) {
      super(graph);

/**
 * A {@link PrimitiveSink} that can compute a hash code after reading the input. Each hasher should
 * translate all multibyte values ({@link #putInt(int)}, {@link #putLong(long)}, etc) to bytes in
 * little-endian order.
 *
 * <p><b>Warning:</b> The result of calling any methods after calling {@link #hash} is undefined.
 *
 * <p><b>Warning:</b> Using a specific character encoding when hashing a {@link CharSequence} with

        // Act
        int bytesWritten = write.writeParameterWordsWireFormat(dst, 0);

        // Assert
        assertEquals(10, bytesWritten, "Should write 10 bytes");
        // Check FID (little-endian)
        assertEquals(0x34, dst[0] & 0xFF);
        assertEquals(0x12, dst[1] & 0xFF);
        // Check count
        assertEquals(10, dst[2] & 0xFF);
        assertEquals(0, dst[3] & 0xFF);

        That's a lot of work they are doing, but if more FastAPI users came to help others like them just a little bit more, it would be much less effort for them (and you and me 😅).

        By asking questions in a structured way (following this) it will be much easier to help you.

* dependable: dependable (do not translate to "confiable" or "fiable")
* list (as in Python list): list
* context manager: context manager (do not translate to "gestor de contexto" or "administrador de contexto")
* a little bit: un poquito
* graph (data structure, as in "dependency graph"): grafo (do not translate to "gráfico")
* form data: form data (do not translate to "datos de formulario" or "datos de form")

If you want to:

* declare the `q` query parameter without a `Query` nor any default value
* declare the path parameter `item_id` using `Path`
* have them in a different order
* not use `Annotated`

...Python has a little special syntax for that.

Pass `*`, as the first parameter of the function.

                        final RC4 rc4 = new RC4(ntlm2SessionKey);
                        rc4.update(masterKey, 0, 16, exchangedKey, 0);
                        /* RC4 was not added to Java until 1.5u7 so let's use our own for a little while longer ...
                        try {
                            Cipher rc4 = Cipher.getInstance("RC4");
                            rc4.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(ntlm2SessionKey, "RC4"));

FastAPI version 0.119.0 introduced partial support for Pydantic v1 from inside of Pydantic v2 (as `pydantic.v1`), to facilitate the migration to v2.

FastAPI 0.126.0 dropped support for Pydantic v1, while still supporting `pydantic.v1` for a little while.

/// warning

The Pydantic team stopped support for Pydantic v1 for the latest versions of Python, starting with **Python 3.14**.

This includes `pydantic.v1`, which is no longer supported in Python 3.14 and above.