# 高级 Python 类型 { #advanced-python-types }

这里有一些在使用 Python 类型时可能有用的额外想法。

## 使用 `Union` 或 `Optional` { #using-union-or-optional }

如果你的代码因为某些原因不能使用 `|`，例如它不是在类型注解里，而是在 `response_model=` 之类的参数中，那么你可以使用 `typing` 中的 `Union` 来代替竖线（`|`）。

例如，你可以声明某个值可以是 `str` 或 `None`：

```python
from typing import Union


def say_hi(name: Union[str, None]):
        print(f"Hi {name}!")
```

`typing` 也提供了一个声明“可能为 `None`”的快捷方式：`Optional`。

}

type metricValue struct {
	Labels map[string]string
	Value  float64
}

// MetricValues - type to set metric values retrieved while loading metrics. A
// value of this type is passed to the `MetricsLoaderFn`.
type MetricValues struct {
	values      map[MetricName][]metricValue
	descriptors map[MetricName]MetricDescriptor
}

func newMetricValues(d map[MetricName]MetricDescriptor) MetricValues {

# Chequeo estricto de Content-Type { #strict-content-type-checking }

Por defecto, **FastAPI** usa un chequeo estricto del header `Content-Type` para request bodies JSON, esto significa que las requests JSON deben incluir un header `Content-Type` válido (p. ej. `application/json`) para que el request body se parse como JSON.

## Riesgo de CSRF { #csrf-risk }

# Строгая проверка HTTP-заголовка Content-Type { #strict-content-type-checking }

По умолчанию **FastAPI** использует строгую проверку HTTP-заголовка `Content-Type` для JSON-тел запросов. Это означает, что JSON-запросы должны включать корректный заголовок `Content-Type` (например, `application/json`), чтобы тело запроса было обработано как JSON.

## Риск CSRF { #csrf-risk }

package cmd

// SetupType - enum for setup type.
type SetupType int

const (
	// UnknownSetupType - starts with unknown setup type.
	UnknownSetupType SetupType = iota

	// FSSetupType - FS setup type enum.
	FSSetupType

	// ErasureSDSetupType - Erasure single drive setup enum.
	ErasureSDSetupType

	// ErasureSetupType - Erasure setup type enum.
	ErasureSetupType

//
// auto* reader = TFE_MonitoringNewCounterReader("name");
// test();
// int64_t value = TFE_MonitoringReadCounter1(reader, "label-value");

// Opaque handle to a reader.
typedef struct TFE_MonitoringCounterReader TFE_MonitoringCounterReader;

// Returns a handle to be used for reading values from streamz counter. The
// counter can have been created with any number of labels.

 * type {@code Iterable<Integer>}, the map won't be able to detect and throw type error.
 *
 * <p>Like any other {@code Map<Class, Object>}, this map may contain entries for primitive types,
 * and a primitive type and its corresponding wrapper type may map to different values.
 *
 * @param <B> the common supertype that all entries must share; often this is simply {@link Object}

// Error implements Error interface
func (b BatchJobYamlErr) Error() string {
	return fmt.Sprintf("%s\n Hint: error near line: %d, col: %d", b.msg, b.line, b.col)
}

// BatchJobKV is a key-value data type which supports wildcard matching
type BatchJobKV struct {
	line, col int
	Key       string `yaml:"key" json:"key"`
	Value     string `yaml:"value" json:"value"`
}

var _ yaml.Unmarshaler = &BatchJobKV{}

  // For LLVM style RTTI.
  static bool classof(const AbstractContext* ptr) {
    return ptr->getKind() == kGraph || ptr->getKind() == kMlir;
  }
};

typedef TracingContext* (*FactoryFunction)(const char* fn_name, TF_Status*);
absl::Status SetDefaultTracingEngine(const char* name);
void RegisterTracingEngineFactory(const ::tensorflow::string& name,

      }
    }

    // Write the payload.
    sink.writeAll(content)
  }

  /**
   * Execute [block] with a new namespace for type hints. Type hints from the enclosing type are no
   * longer usable by the current type's members.
   */
  fun <T> withTypeHint(block: () -> T): T {
    typeHintStack.add(null)
    try {
      return block()
    } finally {