https://github.com/maksimzayats/fastapi-better-di

A utility that allows you to use DI in fastapi without Depends()
https://github.com/maksimzayats/fastapi-better-di

dependency-injection di fastapi fastapi-dependency fastapi-dependency-injection fastapi-di fastapidi

Last synced: 3 months ago
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A utility that allows you to use DI in fastapi without Depends()

• Host: GitHub
• URL: https://github.com/maksimzayats/fastapi-better-di
• Owner: MaksimZayats
• Archived: true
• Created: 2022-04-15T19:01:47.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2023-03-20T14:08:59.000Z (almost 2 years ago)
• Last Synced: 2024-09-28T02:21:50.311Z (3 months ago)
• Topics: dependency-injection, di, fastapi, fastapi-dependency, fastapi-dependency-injection, fastapi-di, fastapidi
• Language: Python
• Homepage:
• Size: 41 KB
• Stars: 10
• Watchers: 1
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

        
# fastapi-better-di

## What is this ?

`fastapi-better-di` is a utility that allows you to use DI in fastapi without Depends()

## Installation

```shell

pip install fastapi_better_di

```

## Examples

```python

# app.py

import uvicorn

from fastapi import FastAPI

from fastapi_better_di.patcher.auto import is_pathed

# functions were patched immediately after import

assert is_pathed(), "Something went wrong"

class MyType:

    def __init__(self, value):

        self.value = value

app = FastAPI()

app.dependency_overrides[MyType] = lambda: MyType(123)

@app.get("/")

def handler(my_type: MyType):  # <- DI without `Depends()`

    assert my_type.value == 123

    return my_type

if __name__ == "__main__":

    uvicorn.run(app)

```

[See all examples](examples)

## Usage

1. Patching:

    * Auto patching: patches classes when importing:

      ```python

      from fastapi_better_di.patcher.auto import is_pathed # The classes were patched immediately after import

      # To check if everything is OK, use assert

      assert is_pathed(), "Something went wrong"

      ```

    * Manual patching: you need to call `patch()` by yourself:

      ```python

      from fastapi_better_di.patcher.manual import patch, is_pathed

      patch()

      

      # To check if everything is OK, use assert

      assert is_pathed(), "Something went wrong"

      ```

    * [Examples](examples)

* **IMPORTANT**: You can still use `= Depends()` without a function as an argument,

  and it won't add unnecessary arguments to the swagger.

  * Related issue: [fastapi issue](https://github.com/tiangolo/fastapi/issues/4118)

* **IMPORTANT**: The main app(`FastAPI`) and `dependency_overrides` must be initialized before importing routers!

## How it works

`fastapi-better-di` simply patch the handler function and add `= Depends(func)` as the default argument