# Tutorial - User Guide

This tutorial shows you how to use **FastAPI** with most of its features, step by step.

Each section gradually builds on the previous ones, but it's structured to separate topics, so that you can go directly to any specific one to solve your specific API needs.

It is also built to work as a future reference so you can come back and see exactly what you need.

## Run the code

# 벤치마크

독립적인 TechEmpower 벤치마크에 따르면 **FastAPI** 애플리케이션이 Uvicorn을 사용하여 <a href="https://www.techempower.com/benchmarks/#section=test&runid=7464e520-0dc2-473d-bd34-dbdfd7e85911&hw=ph&test=query&l=zijzen-7" class="external-link" target="_blank">가장 빠른 Python 프레임워크 중 하나</a>로 실행되며, Starlette와 Uvicorn 자체(내부적으로 FastAPI가 사용하는 도구)보다 조금 아래에 위치합니다.

그러나 벤치마크와 비교를 확인할 때 다음 사항을 염두에 두어야 합니다.

## 벤치마크와 속도

벤치마크를 확인할 때, 일반적으로 여러 가지 유형의 도구가 동등한 것으로 비교되는 것을 볼 수 있습니다.

    level = DeprecationLevel.ERROR,
  )
  fun socketAddress(): InetSocketAddress = socketAddress

  /**
   * Returns true if this route tunnels HTTPS or HTTP/2 through an HTTP proxy.
   * See [RFC 2817, Section 5.2][rfc_2817].
   *
   * [rfc_2817]: http://www.ietf.org/rfc/rfc2817.txt
   */
  fun requiresTunnel(): Boolean {
    if (proxy.type() != Proxy.Type.HTTP) return false
    return (address.sslSocketFactory != null) ||

		}
	}
}

// handleRegularFile sets up the current file reader and padding such that it
// can only read the following logical data section. It will properly handle
// special headers that contain no data section.
func (tr *Reader) handleRegularFile(hdr *Header) error {
	nb := hdr.Size
	if isHeaderOnlyType(hdr.Typeflag) {
		nb = 0
	}
	if nb < 0 {
		return ErrHeader
	}

   *
   * <p><i>Notes:</i> This is an implementation of the algorithm for Lexicographical Permutations
   * Generation, described in Knuth's "The Art of Computer Programming", Volume 4, Chapter 7,
   * Section 7.2.1.2. The iteration order follows the lexicographical order. This means that the
   * first permutation will be in ascending order, and the last will be in descending order.
   *

         * the SMB_COM_SESSION_SETUP_ANDX Response (section 2.2.4.53.2), MUST be set to
         * 0x0000000000000000. For the SMB_COM_SESSION_SETUP_ANDX Response, the SecuritySignature
         * field of the SMB Header SHOULD<226> be set to the SecuritySignature received in the
         * SMB_COM_SESSION_SETUP_ANDX Request (section 2.2.4.53.1).
         */
        if ( this.digest != null && getErrorCode() == 0 ) {

    As always, in FastAPI you can combine `def` and `async def` as needed.

    If you need a refresher about when to use which, check out the section _"In a hurry?"_ in the docs about [`async` and `await`](../async.md#in-a-hurry){.internal-link target=_blank}.

# Benchmarks

Independent TechEmpower benchmarks show **FastAPI** applications running under Uvicorn as <a href="https://www.techempower.com/benchmarks/#section=test&runid=7464e520-0dc2-473d-bd34-dbdfd7e85911&hw=ph&test=query&l=zijzen-7" class="external-link" target="_blank">one of the fastest Python frameworks available</a>, only below Starlette and Uvicorn themselves (used internally by FastAPI).

### OpenAPI-specific `examples`

Since before **JSON Schema** supported `examples` OpenAPI had support for a different field also called `examples`.

This **OpenAPI-specific** `examples` goes in another section in the OpenAPI specification. It goes in the **details for each *path operation***, not inside each JSON Schema.

  //   must be a BER-encoded ASN.1 Certificate structure as described in section 4 of RFC5280.
  //  3. Non-PEM content may appear before or after the "CERTIFICATE" PEM blocks and is unvalidated,
  //   to allow for explanatory text as described in section 5.2 of RFC7468.
  //
  // If more than one PEM block is present, and the definition of the requested spec.signerName