<img src="/img/tutorial/body/image03.png">

You also get error checks for incorrect type operations:

<img src="/img/tutorial/body/image04.png">

This is not by chance, the whole framework was built around that design.

And it was thoroughly tested at the design phase, before any implementation, to ensure it would work with all the editors.

There were even some changes to Pydantic itself to support this.

INHERIT: ../en/mkdocs.env.yml
site_name: FastAPI
site_description: FastAPI framework, high performance, easy to learn, fast to code, ready for production
site_url: https://fastapi.tiangolo.com/
theme:
  name: material
  custom_dir: ../en/overrides
  palette:
  - media: (prefers-color-scheme)
    toggle:
      icon: material/lightbulb-auto
      name: Switch to light mode
  - media: '(prefers-color-scheme: light)'
    scheme: default

import com.google.common.math.StatsTesting.ManyValues;
import com.google.common.testing.EqualsTester;
import com.google.common.testing.SerializableTester;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@link PairedStats}. This tests instances created by {@link
 * PairedStatsAccumulator#snapshot}.
 *
 * @author Pete Gillin
 */

import com.google.common.math.StatsTesting.ManyValues;
import com.google.common.testing.EqualsTester;
import com.google.common.testing.SerializableTester;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@link PairedStats}. This tests instances created by {@link
 * PairedStatsAccumulator#snapshot}.
 *
 * @author Pete Gillin
 */

import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.EnumSet;
import java.util.List;
import java.util.stream.Stream;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for the default implementations of {@code CharSource} methods.
 *
 * @author Colin Decker
 */
@NullUnmarked

import com.google.common.collect.ImmutableSet;
import java.io.Closeable;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link Closer}.
 *
 * @author Colin Decker
 */
@NullUnmarked

import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeoutException;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link AbstractExecutionThreadService}.
 *
 * @author Jesse Wilson
 */
@NullUnmarked

import java.util.concurrent.Future;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests {@link SequentialExecutor}.
 *
 * @author JJ Furman
 */
@NullUnmarked
public class SequentialExecutorTest extends TestCase {

import com.google.common.testing.NullPointerTester;
import com.google.common.testing.SerializableTester;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.Random;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link UnsignedBytes}.
 *
 * @author Kevin Bourrillion
 * @author Louis Wasserman
 */
@NullUnmarked

	testDrwMutexUnlockCallTimeout      = 250 * time.Millisecond
	testDrwMutexForceUnlockCallTimeout = 250 * time.Millisecond
	testDrwMutexRefreshInterval        = 100 * time.Millisecond
)

// TestMain initializes the testing framework
func TestMain(m *testing.M) {
	startLockServers()

	// Initialize locker clients for dsync.
	var clnts []NetLocker
	for i := range nodes {
		clnts = append(clnts, newClient(nodes[i].URL))
	}