* 🔧 Update pre-commit, use ruff format
* ⬆️ Upgrade dependencies, use Ruff for formatting
* 🔧 Update Ruff config
* 🔨 Update lint and format scripts, use Ruff
* 🎨 Format internals with Ruff
* 🎨 Format docs scripts
* 🎨 Format tests
* 🎨 Format extra commas in src for docs
* 📝 Update docs mentioning `@lru_cache()`, use `@lru_cache` instead to keep consistency with the format
* 🎨 Update src for docs, use plain `@lru_cache`
* 🎨 Update src for docs format and docs references
@ -276,7 +276,7 @@ Now we create a dependency that returns a new `config.Settings()`.
```
!!! tip
We'll discuss the `@lru_cache()` in a bit.
We'll discuss the `@lru_cache` in a bit.
For now you can assume `get_settings()` is a normal function.
@ -388,7 +388,7 @@ def get_settings():
we would create that object for each request, and we would be reading the `.env` file for each request. ⚠️
But as we are using the `@lru_cache()` decorator on top, the `Settings` object will be created only once, the first time it's called. ✔️
But as we are using the `@lru_cache` decorator on top, the `Settings` object will be created only once, the first time it's called. ✔️
=== "Python 3.9+"
@ -415,14 +415,14 @@ Then for any subsequent calls of `get_settings()` in the dependencies for the ne
#### `lru_cache` Technical Details
`@lru_cache()` modifies the function it decorates to return the same value that was returned the first time, instead of computing it again, executing the code of the function every time.
`@lru_cache` modifies the function it decorates to return the same value that was returned the first time, instead of computing it again, executing the code of the function every time.
So, the function below it will be executed once for each combination of arguments. And then the values returned by each of those combinations of arguments will be used again and again whenever the function is called with exactly the same combination of arguments.
For example, if you have a function:
```Python
@lru_cache()
@lru_cache
def say_hi(name: str, salutation: str = "Ms."):
return f"Hello {salutation} {name}"
```
@ -474,7 +474,7 @@ In the case of our dependency `get_settings()`, the function doesn't even take a
That way, it behaves almost as if it was just a global variable. But as it uses a dependency function, then we can override it easily for testing.
`@lru_cache()` is part of `functools` which is part of Python's standard library, you can read more about it in the <ahref="https://docs.python.org/3/library/functools.html#functools.lru_cache"class="external-link"target="_blank">Python docs for `@lru_cache()`</a>.
`@lru_cache` is part of `functools` which is part of Python's standard library, you can read more about it in the <ahref="https://docs.python.org/3/library/functools.html#functools.lru_cache"class="external-link"target="_blank">Python docs for `@lru_cache`</a>.
## Recap
@ -482,4 +482,4 @@ You can use Pydantic Settings to handle the settings or configurations for your
* By using a dependency you can simplify testing.
* You can use `.env` files with it.
* Using `@lru_cache()` lets you avoid reading the dotenv file again and again for each request, while allowing you to override it during testing.
* Using `@lru_cache` lets you avoid reading the dotenv file again and again for each request, while allowing you to override it during testing.
Sebastián Ramírez
2 years ago
GitHub