# Body - Updates { #body-updates }

## Update replacing with `PUT` { #update-replacing-with-put }

To update an item you can use the <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PUT" class="external-link" target="_blank">HTTP `PUT`</a> operation.

You can use the `jsonable_encoder` to convert the input data to data that can be stored as JSON (e.g. with a NoSQL database). For example, converting `datetime` to `str`.

    String ROLE = ModelInterpolator.class.getName();

    /**
     * @deprecated Use {@link ModelInterpolator#interpolate(Model, File, ProjectBuilderConfiguration, boolean)} instead.
     */
    @Deprecated
    Model interpolate(Model project, Map<String, ?> context) throws ModelInterpolationException;

    /**
     * @deprecated Use {@link ModelInterpolator#interpolate(Model, File, ProjectBuilderConfiguration, boolean)} instead.
     */

    }

    @Override
    public V replace(final K key, final V value) {
        // use original key
        return parent.replace(key, value);
    }

    @Override
    public V computeIfAbsent(final K key, final Function<? super K, ? extends V> mappingFunction) {
        // use original key
        return parent.computeIfAbsent(key, mappingFunction);
    }

    @Override

    /**
     * Gets the system properties to use for interpolation. The system properties are collected from the runtime
     * environment like {@link System#getProperties()} and environment variables.
     *
     * @return The system properties, never {@code null}.
     */
    Properties getSystemProperties();

    /**

     *
     * @param tc
     *            context to use
     * @param type2
     *            The Type-2 message which this represents a response to.
     * @param targetName
     *            SPN of the target system, optional
     * @param password
     *            The password to use when constructing the response.
     * @param domain

* **`400 - 499`** are for "Client error" responses. These are the second type you would probably use the most.
    * An example is `404`, for a "Not Found" response.
    * For generic errors from the client, you can just use `400`.
* `500 - 599` are for server errors. You almost never use them directly. When something goes wrong at some part in your application code, or server, it will automatically return one of these status codes.

### Using your local FastAPI

If you create a Python file that imports and uses FastAPI, and run it with the Python from your local environment, it will use your cloned local FastAPI source code.

And if you update that local FastAPI source code when you run that Python file again, it will use the fresh version of FastAPI you just edited.

That way, you don't have to "install" your local version to be able to test every change.

## Create and Use Env Vars { #create-and-use-env-vars }

You can **create** and use environment variables in the **shell (terminal)**, without needing Python:

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console
// You could create an env var MY_NAME with
$ export MY_NAME="Wade Wilson"

// Then you could use it with other programs, like
$ echo "Hello $MY_NAME"

If you have an older version, you would get errors when trying to use `Annotated`.

Make sure you [Upgrade the FastAPI version](../deployment/versions.md#upgrading-the-fastapi-versions){.internal-link target=_blank} to at least 0.95.1 before using `Annotated`.

///

## Use `Annotated` in the type for the `q` parameter { #use-annotated-in-the-type-for-the-q-parameter }

/*
 * Copyright (C) 2011 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License