FastAPI is a modern, fast (high-performance), web framework for building APIs with Python 3.6+ based on standard Python type hints.
FastAPI 是一个用于构建 API 的现代、快速（高性能）的 web 框架，使用基于类型提示的 Python 3.6 及更高版本。
The key features are:
关键特性:
* **Fast**: Very high performance, on par with **NodeJS** and **Go** (thanks to Starlette and Pydantic). [One of the fastest Python frameworks available](#performance).
* **Fast to code**: Increase the speed to develop features by about 200% to 300% *.
* **高效编码**：提高功能开发速度约 200％ 至 300％。*
* **Fewer bugs**: Reduce about 40% of human (developer) induced errors. *
* **更少 bug**：减少约 40％ 的人为（开发者）导致错误。*
* **Intuitive**: Great editor support. <abbrtitle="also known as auto-complete, autocompletion, IntelliSense">Completion</abbr> everywhere. Less time debugging.
* **Easy**: Designed to be easy to use and learn. Less time reading docs.
* **简单**：设计的易于使用和学习，减少阅读文档时间。
* **Short**: Minimize code duplication. Multiple features from each parameter declaration. Fewer bugs.
* **简短**：减少代码重复。通过不同的参数声明实现丰富功能。bug 更少。
* **Robust**: Get production-ready code. With automatic interactive documentation.
* **健壮**：生产可用级别的代码。以及自动生成的交互式文档。
* **Standards-based**: Based on (and fully compatible with) the open standards for APIs: <ahref="https://github.com/OAI/OpenAPI-Specification"class="external-link"target="_blank">OpenAPI</a> (previously known as Swagger) and<ahref="http://json-schema.org/"class="external-link"target="_blank">JSON Schema</a>.
* **标准化**：基于 API 的相关开放标准并完全兼容：<ahref="https://github.com/OAI/OpenAPI-Specification"class="external-link"target="_blank">OpenAPI</a> (以前被称为 Swagger) 和<ahref="http://json-schema.org/"class="external-link"target="_blank">JSON Schema</a>。
<small>* estimation based on tests on an internal development team, building production applications.</small>
<small>* 根据对某个构建线上应用的内部开发团队所进行的测试估算得出。</small>
## Opinions
## 评价
"*[...] I'm using **FastAPI** a ton these days. [...] I'm actually planning to use it for all of my team's **ML services at Microsoft**. Some of them are getting integrated into the core **Windows** product and some **Office** products.*"
"*Honestly, what you've built looks super solid and polished. In many ways, it's what I wanted **Hug** to be - it's really inspiring to see someone build that.*"
"*If you're looking to learn one **modern framework** for building REST APIs, check out **FastAPI** [...] It's fast, easy to use and easy to learn [...]*"
If you are building a <abbrtitle="Command Line Interface">CLI</abbr> app to be used in the terminal instead of a web API, check out<ahref="https://typer.tiangolo.com/"class="external-link"target="_blank">**Typer**</a>.
如果你正在开发一个在终端中运行的<abbrtitle="Command Line Interface">命令行</abbr>应用而不是 web API，不妨试下<ahref="https://typer.tiangolo.com/"class="external-link"target="_blank">**Typer**</a>。
**Typer** is FastAPI's little sibling. And it's intended to be the **FastAPI of CLIs**. ⌨️ 🚀
You will also need an ASGI server, for production such as<ahref="http://www.uvicorn.org"class="external-link"target="_blank">Uvicorn</a>or<ahref="https://gitlab.com/pgjones/hypercorn"class="external-link"target="_blank">Hypercorn</a>.
If you don't know, check the _"In a hurry?"_ section about<ahref="https://fastapi.tiangolo.com/async/#in-a-hurry"target="_blank">`async` and `await` in the docs</a>.
如果你不知道是否会用到，可以查看文档的 _"In a hurry?"_ 章节中<ahref="https://fastapi.tiangolo.com/async/#in-a-hurry"target="_blank">关于 `async` 和 `await` 的部分</a>。
</details>
</details>
### Run it
### 运行
Run the server with:
通过以下命令运行服务器：
<divclass="termy">
<divclass="termy">
@ -190,54 +186,54 @@ $ uvicorn main:app --reload
</div>
</div>
<detailsmarkdown="1">
<detailsmarkdown="1">
<summary>About the command<code>uvicorn main:app --reload</code>...</summary>
* `--reload`: make the server restart after code changes. Only do this for development.
* `--reload`：让服务器在更新代码后重新启动。仅在开发时使用该选项。
</details>
</details>
### Check it
### 检查
Open your browser at<ahref="http://127.0.0.1:8000/items/5?q=somequery"class="external-link"target="_blank">http://127.0.0.1:8000/items/5?q=somequery</a>.
You will see the automatic interactive API documentation (provided by<ahref="https://github.com/swagger-api/swagger-ui"class="external-link"target="_blank">Swagger UI</a>):
你会看到自动生成的交互式 API 文档（由<ahref="https://github.com/swagger-api/swagger-ui"class="external-link"target="_blank">Swagger UI</a>生成）：
You will see the alternative automatic documentation (provided by<ahref="https://github.com/Rebilly/ReDoc"class="external-link"target="_blank">ReDoc</a>):
* Then click on the "Execute" button, the user interface will communicate with your API, send the parameters, get the results and show them on the screen:
* 然后点击 "Execute" 按钮，用户界面将会和 API 进行通信，发送参数，获取结果并在屏幕上展示：
In summary, you declare **once** the types of parameters, body, etc. as function parameters.
总的来说，你就像声明函数的参数类型一样只声明了**一次**请求参数、请求体等的类型。
You do that with standard modern Python types.
你使用了标准的现代 Python 类型来完成声明。
You don't have to learn a new syntax, the methods or classes of a specific library, etc.
你不需要去学习新的语法、了解特定库的方法或类，等等。
Just standard **Python 3.6+**.
只需要使用标准的 **Python 3.6 及更高版本**。
For example, for an `int`:
举个例子，比如声明 `int` 类型：
```Python
```Python
item_id: int
item_id: int
```
```
or for a more complex `Item` model:
或者一个更复杂的 `Item` 模型：
```Python
```Python
item: Item
item: Item
```
```
...and with that single declaration you get:
......在进行一次声明之后，你将获得：
* Editor support, including:
* 编辑器支持，包括：
* Completion.
* 自动补全
* Type checks.
* 类型检查
* Validation of data:
* 数据校验：
* Automatic and clear errors when the data is invalid.
* 在校验失败时自动生成清晰的错误信息
* Validation even for deeply nested JSON objects.
* 对多层嵌套的 JSON 对象依然执行校验
* <abbrtitle="also known as: serialization, parsing, marshalling">Conversion</abbr>of input data: coming from the network to Python data and types. Reading from:
* <abbrtitle="also known as: serialization, parsing, marshalling">Conversion</abbr>of output data: converting from Python data and types to network data (as JSON):
* How to set **validation constraints** as `maximum_length` or `regex`.
* 如何设置**校验约束**如 `maximum_length` 或者 `regex`。
* A very powerful and easy to use**<abbrtitle="also known as components, resources, providers, services, injectables">Dependency Injection</abbr>** system.
* extremely easy tests based on `requests` and `pytest`
* 基于 `requests` 和 `pytest` 的极其简单的测试
* **CORS**
* **CORS**
* **Cookie Sessions**
* **Cookie Sessions**
* ...and more.
* ......以及更多
## 性能
## Performance
Independent TechEmpower benchmarks show **FastAPI** applications running under Uvicorn as<ahref="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). (*)
* <ahref="https://github.com/esnme/ultrajson"target="_blank"><code>ujson</code></a> - for faster JSON <abbrtitle="converting the string that comes from an HTTP request into Python data">"parsing"</abbr>.
* <ahref="https://andrew-d.github.io/python-multipart/"target="_blank"><code>python-multipart</code></a> - Required if you want to support form <abbrtitle="converting the string that comes from an HTTP request into Python data">"parsing"</abbr>, with `request.form()`.
* <ahref="https://pyyaml.org/wiki/PyYAMLDocumentation"target="_blank"><code>pyyaml</code></a> - Required for Starlette's `SchemaGenerator` support (you probably don't need it with FastAPI).
Xie Wei
5 years ago
GitHub