通过声明变量的类型，编辑器和一些工具能给你提供更好的支持。

这只是一个关于 Python 类型提示的**快速入门 / 复习**。它仅涵盖与 **FastAPI** 一起使用所需的最少部分...实际上只有很少一点。

整个 **FastAPI** 都基于这些类型提示构建，它们带来了许多优点和好处。

但即使你不会用到 **FastAPI**，了解一下类型提示也会让你从中受益。

/// note

如果你已经精通 Python，并且了解关于类型提示的一切知识，直接跳到下一章节吧。

///

## 动机

让我们从一个简单的例子开始：

```Python
{!../../docs_src/python_types/tutorial001.py!}
```

运行这段程序将输出：

```
John Doe
```

	//	#define A(x)
	// and
	//	#define A (x)
	// distinctly: the first is a macro with arguments, the second without.
	// Distinguish these cases using the column number, since we don't
	// see the space itself. Note that text/scanner reports the position at the
	// end of the token. It's where you are now, and you just read this token.
	if tok == '(' && in.Stack.Col() == prevCol+1 {
		// Macro has arguments. Scan list of formals.

 *
 * <p>Instances of this class may be used by multiple threads concurrently. All operations are
 * atomic unless otherwise noted.
 *
 * <p>Instances of this class are serializable if the keys are serializable.
 *
 * <p><b>Note:</b> If your values are always positive and less than 2^31, you may wish to use a
 * {@link com.google.common.collect.Multiset} such as {@link
 * com.google.common.collect.ConcurrentHashMultiset} instead.
 *

import org.apache.maven.model.validation.ModelValidator;

import static java.util.Objects.requireNonNull;

/**
 * A factory to create model builder instances when no dependency injection is available. Note: This class is
 * only meant as a utility for developers that want to employ the model builder outside the Maven build system, Maven

    xStats.addAll(values.xStats());
    if (yStats.count() == 0) {
      sumOfProductsOfDeltas = values.sumOfProductsOfDeltas();
    } else {
      // This is a generalized version of the calculation in add(double, double) above. Note that
      // non-finite inputs will have sumOfProductsOfDeltas = NaN, so non-finite values will result
      // in NaN naturally.
      sumOfProductsOfDeltas +=
          values.sumOfProductsOfDeltas()

     * the key would be inserted into the list: the index of the next higher element in the list, or
     * {@code list.size()} if there is no such element.
     *
     * <p>Note that the return value will be {@code >= 0} if and only if there is an element of the
     * list that compares as equal to the key.
     *

```
Alors, déclarez vos *fonctions de chemins* avec `async def` comme ceci :

```Python hl_lines="2"
@app.get('/')
async def read_results():
    results = await some_library()
    return results
```

/// note

Vous pouvez uniquement utiliser `await` dans les fonctions créées avec `async def`.

///

---

    define_values = {"override_eigen_strong_inline": "true"},
    visibility = ["//visibility:public"],
)

# This flag specifies whether TensorFlow 2.0 API should be built instead
# of 1.* API. Note that TensorFlow 2.0 API is currently under development.
config_setting(
    name = "api_version_2",
    define_values = {"tf_api_version": "2"},
    visibility = ["//visibility:public"],
)

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A general-purpose bimap implementation using any two backing {@code Map} instances.
 *
 * <p>Note that this class contains {@code equals()} calls that keep it from supporting {@code
 * IdentityHashMap} backing maps.
 *
 * @author Kevin Bourrillion
 * @author Mike Bostock
 */
@GwtCompatible(emulated = true)

// license that can be found in the LICENSE file.

/*
Package zip provides support for reading and writing ZIP archives.

See the [ZIP specification] for details.

This package does not support disk spanning.

A note about ZIP64:

To be backwards compatible the FileHeader has both 32 and 64 bit Size
fields. The 64 bit fields will always contain the correct value and
for normal archives both fields will be the same. For files requiring