Je declareert de "vorm" van de data als klassen met attributen.

Elk attribuut heeft een type.

Vervolgens maak je een instantie van die klasse met een aantal waarden en het valideert de waarden, converteert ze naar het juiste type (als dat het geval is) en geeft je een object met alle data terug.

Daarnaast krijg je volledige editorondersteuning met dat resulterende object.

Een voorbeeld uit de officiële Pydantic-documentatie:

// for the file metadata. [Writer] takes ownership of fh and may mutate
// its fields. The caller must not modify fh after calling [Writer.CreateHeader].
//
// This returns a [Writer] to which the file contents should be written.
// The file's contents must be written to the io.Writer before the next
// call to [Writer.Create], [Writer.CreateHeader], [Writer.CreateRaw], or [Writer.Close].

     *
     * @param props
     *            Property set. Must not be {@literal null}.
     * @param file
     *            File. Must not be {@literal null}.
     * @param encoding
     *            Encoding. Must not be {@literal null} or empty.
     */
    public static void load(final Properties props, final File file, final String encoding) {

    public void test_execute_withBooleanQuery() {
        // Create a simple BooleanQuery with MUST clause
        BooleanQuery.Builder boolQueryBuilder = new BooleanQuery.Builder();
        TermQuery termQuery = new TermQuery(new Term("field", "value"));
        boolQueryBuilder.add(termQuery, BooleanClause.Occur.MUST);
        BooleanQuery booleanQuery = boolQueryBuilder.build();

# ---------------
constraints.AssertFalse.message = {item} muss falsch sein.
constraints.AssertTrue.message = {item} muss wahr sein.
constraints.DecimalMax.message = {item} muss kleiner als {value} sein.
constraints.DecimalMin.message = {item} muss größer als {value} sein.
constraints.Digits.message = {item} muss eine Zahl sein. (erwartet: <Zahl>.<Zahl>)
constraints.Future.message = {item} muss ein zukünftiger Wert sein.

     * @param schema
     *            Schema file. Must not be {@literal null}.
     * @return {@link Schema}
     */
    public static Schema newSchema(final SchemaFactory factory, final File schema) {
        assertArgumentNotNull("factory", factory);
        assertArgumentNotNull("schema", schema);

        try {
            return factory.newSchema(schema);

    protected FieldUtil() {
    }

    /**
     * Returns the value of a {@code static} field represented by the given {@link Field}.
     *
     * @param <T> the type of the field
     * @param field the field (must not be {@literal null})
     * @return the value represented by the {@code static} field
     * @throws IllegalAccessRuntimeException if the field cannot be accessed
     * @see Field#get(Object)
     */

     *
     * @param path
     *            The file path. Must not be {@literal null} or empty.
     * @param encoding
     *            The encoding. Must not be {@literal null} or empty.
     * @return The text read from the file.
     */
    public static String readText(final String path, final String encoding) {
        assertArgumentNotEmpty("path", path);

    checkNotNull(funnel);
    checkArgument(
        expectedInsertions >= 0, "Expected insertions (%s) must be >= 0", expectedInsertions);
    checkArgument(fpp > 0.0, "False positive probability (%s) must be > 0.0", fpp);
    checkArgument(fpp < 1.0, "False positive probability (%s) must be < 1.0", fpp);
    return Collector.of(
        () -> BloomFilter.create(funnel, expectedInsertions, fpp),
        BloomFilter::put,

				prog.To = a[2]
				break
			}
			if arch.IsARMBFX(op) {
				// a[0] and a[1] must be constants, a[2] must be a register
				prog.From = a[0]
				prog.AddRestSource(a[1])
				prog.To = a[2]
				break
			}
			// Otherwise the 2nd operand (a[1]) must be a register.
			prog.From = a[0]
			prog.Reg = p.getRegister(prog, op, &a[1])
			prog.To = a[2]
		case sys.AMD64: