1.3. Architecture

1.3.1. Technology Stack

• Uvicorn

• Starlette

• Pydantic

• Python type annotations (available since Python 3.5)

1.3.2. Uvicorn

• Uvicorn is a lightning-fast ASGI server implementation, using uvloop and httptools.

• Until recently Python has lacked a minimal low-level server/application interface for asyncio frameworks. The ASGI specification fills this gap, and means we're now able to start building a common set of tooling usable across all asyncio frameworks.

• ASGI should help enable an ecosystem of Python web frameworks that are highly competitive against Node and Go in terms of achieving high throughput in IO-bound contexts. It also provides support for HTTP/2 and WebSockets, which cannot be handled by WSGI.

• Uvicorn currently supports HTTP/1.1 and WebSockets. Support for HTTP/2 is planned.

• Source: 1

1.3.3. Starlette

• Starlette is a lightweight ASGI framework/toolkit, which is ideal for building high performance asyncio services.

• It is production-ready, and gives you the following:

  • Seriously impressive performance.

  • WebSocket support.

  • GraphQL support.

  • In-process background tasks.

  • Startup and shutdown events.

  • Test client built on requests.

  • CORS, GZip, Static Files, Streaming responses.

  • Session and Cookie support.

  • 100% test coverage.

  • 100% type annotated codebase.

  • Zero hard dependencies.

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1.3.4. Pydantic

• Data validation and settings management using python type annotations.

• pydantic enforces type hints at runtime, and provides user friendly errors when data is invalid.

• Define how data should be in pure, canonical python; validate it with pydantic.

• So pydantic uses some cool new language features, but why should I actually go and use it?

  • There's no new schema definition micro-language to learn.

  • pydantic's BaseSettings class allows pydantic to be used in both a "validate this request data" context and in a "load my system settings" context

  • In benchmarks pydantic is faster than all other tested libraries

  • validate complex structures

  • pydantic allows custom data types to be defined or you can extend validation with methods on a model decorated with the validator decorator.

  • dataclasses integration

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1.3.5. References

1

Uvicorn official documentation. Retrieved: 2021-02-23. URL: https://www.uvicorn.org

2

Pydantic official documentation. Retrieved: 2021-02-23. URL: https://pydantic-docs.helpmanual.io

3

Starlette official documentation. Retrieved: 2021-02-23. URL: https://www.starlette.io