Searching for package file structure from directories with
             <font color="#3465A4">__init__.py</font> files
             Importing from <font color="#75507B">/home/user/code/</font><font color="#AD7FA8">awesomeapp</font>

   <span style="background-color:#007166"><font color="#D3D7CF"> module </font></span>  🐍 main.py

            V1Field["Pydantic v1 Model"]
        end
    end

    style V2 fill:#f9fff3
    style V1 fill:#fff6f0
    style V1Field fill:#fff6f0
    style V2Field fill:#f9fff3
```

In some cases, it's even possible to have both Pydantic v1 and v2 models in the same **path operation** in your FastAPI app:

{* ../../docs_src/pydantic_v1_in_v2/tutorial003_an_py310.py hl[2:3,6,12,21:22] *}

             Searching for package file structure from directories with
             <font color="#3465A4">__init__.py</font> files
             Importing from <font color="#75507B">/home/user/code/</font><font color="#AD7FA8">awesomeapp</font>

   <span style="background-color:#007166"><font color="#D3D7CF"> module </font></span>  🐍 main.py

 * annotation implies nothing about the quality or performance of the API in question, only the fact
 * that it is not "API-frozen."
 *
 * <p>It is generally safe for <i>applications</i> to depend on beta APIs, at the cost of some extra
 * work during upgrades. However it is generally inadvisable for <i>libraries</i> (which get
 * included on users' CLASSPATHs, outside the library developers' control) to do so.
 *
 * @author Kevin Bourrillion
 */

 * annotation implies nothing about the quality or performance of the API in question, only the fact
 * that it is not "API-frozen."
 *
 * <p>It is generally safe for <i>applications</i> to depend on beta APIs, at the cost of some extra
 * work during upgrades. However it is generally inadvisable for <i>libraries</i> (which get
 * included on users' CLASSPATHs, outside the library developers' control) to do so.
 *
 * @author Kevin Bourrillion
 */

   * The type of ordering that this object specifies.
   *
   * <ul>
   *   <li>UNORDERED: no order is guaranteed.
   *   <li>STABLE: ordering is guaranteed to follow a pattern that won't change between releases.
   *       Some methods may have stronger guarantees.
   *   <li>INSERTION: insertion ordering is guaranteed.
   *   <li>SORTED: ordering according to a supplied comparator is guaranteed.
   * </ul>
   */
  public enum Type {

             Searching for package file structure from directories
             with <font color="#3465A4">__init__.py</font> files
             Importing from <font color="#75507B">/home/user/code/</font><font color="#AD7FA8">awesomeapp</font>

   <span style="background-color:#007166"><font color="#D3D7CF"> module </font></span>  🐍 main.py

 * the License.
 */

package com.google.common.base;

import com.google.common.annotations.GwtCompatible;

/**
 * A time source; returns a time value representing the number of nanoseconds elapsed since some
 * fixed but arbitrary point in time. Note that most users should use {@link Stopwatch} instead of
 * interacting with this class directly.
 *

 *   <li>{@link StandardSystemProperty}
 *   <li>{@link Stopwatch}
 *   <li>{@link Throwables}
 *   <li>{@link Verify}
 * </ul>
 *
 * <h3>The rest</h3>
 *
 * This package also contains some classes with niche use cases (e.g., {@link Utf8} and {@link
 * Defaults}), as well as a number of classes that have been superseded by additions to the JDK.
 */
@CheckReturnValue
@NullMarked
package com.google.common.base;

# JSON Compatible Encoder { #json-compatible-encoder }

There are some cases where you might need to convert a data type (like a Pydantic model) to something compatible with JSON (like a `dict`, `list`, etc).

For example, if you need to store it in a database.

For that, **FastAPI** provides a `jsonable_encoder()` function.

## Using the `jsonable_encoder` { #using-the-jsonable-encoder }