But it was created before there existed Python type hints. So, to define every <abbr title="the definition of how data should be formed">schema</abbr> you need to use specific utils and classes provided by Marshmallow.

/// check | Inspired **FastAPI** to

Use code to define "schemas" that provide data types and validation, automatically.

///

So, you can declare deeply nested JSON "objects" with specific attribute names, types and validations.

All that, arbitrarily nested.

### Define a submodel { #define-a-submodel }

For example, we can define an `Image` model:

{* ../../docs_src/body_nested_models/tutorial004_py310.py hl[7:9] *}

### Use the submodel as a type { #use-the-submodel-as-a-type }

**FastAPI** is based on **OpenAPI**.

That's what makes it possible to have multiple automatic interactive documentation interfaces, code generation, etc.

OpenAPI has a way to define multiple security "schemes".

By using them, you can take advantage of all these standard-based tools, including these interactive documentation systems.

OpenAPI defines the following security schemes:

```kotlin
    dependencies {
       // define a BOM and its version
       implementation(platform("com.squareup.okhttp3:okhttp-bom:5.1.0"))

       // define any required OkHttp artifacts without version
       implementation("com.squareup.okhttp3:okhttp")
       implementation("com.squareup.okhttp3:logging-interceptor")

But as you go away from the counter and sit at the table with a number for your turn, you can switch 🔀 your attention to your crush, and "work" ⏯ 🤓 on that. Then you are again doing something very "productive" as is flirting with your crush 😍.

Production'da nasıl oldugunu görmek için şu bölüme bakın [Deployment](deployment/index.md){.internal-link target=_blank}.

## `async` ve `await`

If you can use the **latest versions of Python**, use the examples for the latest version, those will have the **best and simplest syntax**, for example, "**Python 3.10+**".

#### List { #list }

For example, let's define a variable to be a `list` of `str`.

//// tab | Python 3.9+

Declare the variable, with the same colon (`:`) syntax.

As the type, put `list`.

		lines(
			"#ifdef A",
			"#ifdef B",
			"#define C 1234",
			"#else",
			"#define C 5678",
			"#endif",
			"#endif",
			"C",
		),
		"C.\n",
	},
	{
		"nested #define",
		lines(
			"#define A #define B THIS",
			"A",
			"B",
		),
		"THIS.\n",
	},
	{
		"nested #define with args",
		lines(
			"#define A #define B(x) x",
			"A",
			"B(THIS)",
		),

3. This `yield from` tells the function to iterate over that thing named `file_like`. And then, for each part iterated, yield that part as coming from this generator function (`iterfile`).

    So, it is a generator function that transfers the "generating" work to something else internally.

#ifndef TENSORFLOW_C_C_API_MACROS_H_
#define TENSORFLOW_C_C_API_MACROS_H_

#ifdef SWIG
#define TF_CAPI_EXPORT
#else
#if defined(_WIN32)
#ifdef TF_COMPILE_LIBRARY
#define TF_CAPI_EXPORT __declspec(dllexport)
#else
#define TF_CAPI_EXPORT __declspec(dllimport)
#endif  // TF_COMPILE_LIBRARY
#else
#ifdef TF_CAPI_WEAK
#define TF_CAPI_EXPORT \
  __attribute__((visibility("default"))) __attribute((weak))