當你安裝 FastAPI（例如使用 `pip install "fastapi[standard]"`），它會包含一個叫做 `fastapi-cli` 的套件，這個套件提供了 `fastapi` 命令。

要運行你的 FastAPI 應用程式來進行開發，你可以使用 `fastapi dev` 命令：

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:single">main.py</u>
<font color="#3465A4">INFO    </font> Using path <font color="#3465A4">main.py</font>

file: org.apache.spark.rdd.RDD[String] = s3a://testbucket/testdata MapPartitionsRDD[1] at textFile at <console>:24

scala> val counts = file.flatMap(line => line.split(" ")).map(word => (word, 1)).reduceByKey(_ + _)
counts: org.apache.spark.rdd.RDD[(String, Int)] = ShuffledRDD[4] at reduceByKey at <console>:25

scala> counts.saveAsTextFile("s3a://testbucket/wordcount")
```

```
fastapi>=0.68.0,<0.69.0
pydantic>=1.8.0,<2.0.0
uvicorn>=0.15.0,<0.16.0
```

E você normalmente instalaria essas dependências de pacote com `pip`, por exemplo:

<div class="termy">

```console
$ pip install -r requirements.txt
---> 100%
Successfully installed fastapi pydantic uvicorn
```

</div>

/// info

Há outros formatos e ferramentas para definir e instalar dependências de pacote.

```
fastapi>=0.68.0,<0.69.0
pydantic>=1.8.0,<2.0.0
uvicorn>=0.15.0,<0.16.0
```

Und normalerweise würden Sie diese Paketabhängigkeiten mit `pip` installieren, zum Beispiel:

<div class="termy">

```console
$ pip install -r requirements.txt
---> 100%
Successfully installed fastapi pydantic uvicorn
```

</div>

/// info

# First Steps

The simplest FastAPI file could look like this:

{* ../../docs_src/first_steps/tutorial001.py *}

Copy that to a file `main.py`.

Run the live server:

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:single">main.py</u>
<font color="#3465A4">INFO    </font> Using path <font color="#3465A4">main.py</font>

    val groovy = "$groovyGroup:groovy"
    val groovyAnt = "$groovyGroup:groovy-ant"
    val groovyAstbuilder = "$groovyGroup:groovy-astbuilder"
    val groovyConsole = "$groovyGroup:groovy-console"
    val groovyDateUtil = "$groovyGroup:groovy-dateutil"
    val groovyDatetime = "$groovyGroup:groovy-datetime"
    val groovyDoc = "$groovyGroup:groovy-groovydoc"
    val groovyJson = "$groovyGroup:groovy-json"

	github.com/klauspost/reedsolomon v1.12.4
	github.com/lib/pq v1.10.9
	github.com/lithammer/shortuuid/v4 v4.0.0
	github.com/miekg/dns v1.1.62
	github.com/minio/cli v1.24.2
	github.com/minio/console v1.7.1
	github.com/minio/csvparser v1.0.0
	github.com/minio/dnscache v0.1.1
	github.com/minio/dperf v0.6.0
	github.com/minio/highwayhash v1.0.3
	github.com/minio/kms-go/kes v0.3.0
	github.com/minio/kms-go/kms v0.4.0

* **Suporte ao editor**.
* **Verificações de tipo**.

... e o **FastAPI** usa as mesmas declarações para:

* **Definir requisitos**: dos parâmetros de rota, parâmetros da consulta, cabeçalhos, corpos, dependências, etc.
* **Converter dados**: da solicitação para o tipo necessário.
* **Validar dados**: provenientes de cada solicitação:

In this example, the program is asking for Go 1.21 semantics and
then asking for the old pre-Go 1.21 `panic(nil)` behavior and the
new Go 1.23 `asynctimerchan=0` behavior.

Only the work module's `go.mod` is consulted for `godebug` directives.
Any directives in required dependency modules are ignored.
It is an error to list a `godebug` with an unrecognized setting.
(Toolchains older than Go 1.23 reject all `godebug` lines, since they do not

## Installation

Create and activate a <a href="https://fastapi.tiangolo.com/virtual-environments/" class="external-link" target="_blank">virtual environment</a> and then install FastAPI:

<div class="termy">

```console
$ pip install "fastapi[standard]"

---> 100%
```

</div>

**Note**: Make sure you put `"fastapi[standard]"` in quotes to ensure it works in all terminals.

## Example

### Create it