def main(user_id: str):
    return user_id


# Een Pydantic model
class User(BaseModel):
    id: int
    name: str
    joined: date
```

Vervolgens kan je het op deze manier gebruiken:

```Python
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {
    "id": 4,
    "name": "Mary",
    "joined": "2018-11-30",
}

      absl::Status* status) = 0;

  // Create an operation to perform op execution
  ImmediateExecutionOperation* CreateOperation() override = 0;

  // Returns whether the runtime is backed by TFRT or the legacy TF Eager
  // Runtime. This is necessary to decouple runtime-dependent
  // code that is layered on top of the runtime.
  virtual bool UsesTFRT() = 0;

  // List attributes of available devices

// If the offset is non-sensible, then this uses an offset of zero.
func timeZone(offset time.Duration) *time.Location {
	const (
		minOffset   = -12 * time.Hour  // E.g., Baker island at -12:00
		maxOffset   = +14 * time.Hour  // E.g., Line island at +14:00
		offsetAlias = 15 * time.Minute // E.g., Nepal at +5:45
	)
	offset = offset.Round(offsetAlias)

.table-warning:hover {\n  background-color: #ffe8a1;\n}\n\n.table-hover .table-warning:hover > td,\n.table-hover .table-warning:hover > th {\n  background-color: #ffe8a1;\n}\n\n.table-danger,\n.table-danger > th,\n.table-danger > td {\n  background-color: #f5c6cb;\n}\n\n.table-danger th,\n.table-danger td,\n.table-danger thead th,\n.table-danger tbody + tbody {\n  border-color: #ed969e;\n}\n\n.table-hover .table-danger:hover {\n  background-color: #f1b0b7;\n}\n\n.table-hover .table-danger:hover > td,\n.table-hover...

import java.util.Set;
import java.util.function.ObjIntConsumer;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Basic implementation of {@code Multiset<E>} backed by an instance of {@code Map<E, Count>}.
 *
 * <p>For serialization to work, the subclass must specify explicit {@code readObject} and {@code
 * writeObject} methods.
 *
 * @author Kevin Bourrillion
 */

# 更多模型

书接上文，多个关联模型这种情况很常见。

特别是用户模型，因为：

* **输入模型**应该含密码
* **输出模型**不应含密码
* **数据库模型**需要加密的密码

/// danger | "危险"

千万不要存储用户的明文密码。始终存储可以进行验证的**安全哈希值**。

如果不了解这方面的知识，请参阅[安全性中的章节](security/simple-oauth2.md#password-hashing){.internal-link target=_blank}，了解什么是**密码哈希**。

///

## 多个模型

下面的代码展示了不同模型处理密码字段的方式，及使用位置的大致思路：

//// tab | Python 3.10+

```Python hl_lines="7  9  14  20  22  27-28  31-33  38-39"

            Version version,
            String string,
            String sourceHint,
            InputLocationTracker tracker,
            String banned) {
        if (string != null) {
            for (int i = string.length() - 1; i >= 0; i--) {
                if (banned.indexOf(string.charAt(i)) >= 0) {
                    addViolation(
                            problems,
                            severity,

  @CanIgnoreReturnValue
  boolean setCount(@ParametricNullness E element, int oldCount, int newCount);

  // Views

  /**
   * Returns the set of distinct elements contained in this multiset. The element set is backed by
   * the same data as the multiset, so any change to either is immediately reflected in the other.
   * The order of the elements in the element set is unspecified.
   *

```Python hl_lines="17-18"
{!../../docs_src/response_model/tutorial002.py!}
```

现在，每当浏览器使用一个密码创建用户时，API 都会在响应中返回相同的密码。

在这个案例中，这可能不算是问题，因为用户自己正在发送密码。

但是，如果我们在其他的*路径操作*中使用相同的模型，则可能会将用户的密码发送给每个客户端。

/// danger

永远不要存储用户的明文密码，也不要在响应中发送密码。

///

## 添加输出模型

相反，我们可以创建一个有明文密码的输入模型和一个没有明文密码的输出模型：

//// tab | Python 3.10+

```Python hl_lines="9  11  16"

	Unlock(lkCtx LockContext)
	GetRLock(ctx context.Context, timeout *dynamicTimeout) (lkCtx LockContext, timedOutErr error)
	RUnlock(lkCtx LockContext)
}

// LockContext lock context holds the lock backed context and canceler for the context.
type LockContext struct {
	ctx    context.Context
	cancel context.CancelFunc
}

// Context returns lock context
func (l LockContext) Context() context.Context {
	return l.ctx