"være", "kom", "noen", "noe", "ville", "dere", "som", "deres", "kun", "ja", "etter", "ned", "skulle", "denne", "for", "deg", "si", "sine", "sitt", "mot", "å", "meget", "hvorfor", "dette", "disse", "uten", "hvordan", "ingen", "din", "ditt", "blir", "samme", "hvilken", "hvilke", "sånn", "inni", "mellom", "vår", "hver", "hvem", "vors", "hvis", "både", "bare", "enn", "fordi", "før", "mange", "også", "slik", "vært", "være", "båe", "begge", "siden", "dykk", "dykkar", "dei", "deira", "deires", "deim", "di",...

"være", "kom", "noen", "noe", "ville", "dere", "som", "deres", "kun", "ja", "etter", "ned", "skulle", "denne", "for", "deg", "si", "sine", "sitt", "mot", "å", "meget", "hvorfor", "dette", "disse", "uten", "hvordan", "ingen", "din", "ditt", "blir", "samme", "hvilken", "hvilke", "sånn", "inni", "mellom", "vår", "hver", "hvem", "vors", "hvis", "både", "bare", "enn", "fordi", "før", "mange", "også", "slik", "vært", "være", "båe", "begge", "siden", "dykk", "dykkar", "dei", "deira", "deires", "deim", "di",...

<img src="/img/tutorial/bigger-applications/image01.png">

## Include the same router multiple times with different `prefix` { #include-the-same-router-multiple-times-with-different-prefix }

You can also use `.include_router()` multiple times with the *same* router using different prefixes.

This could be useful, for example, to expose the same API under different prefixes, e.g. `/api/v1` and `/api/latest`.

This will be especially useful when you use it in a **large code base** where you use **the same dependencies** over and over again in **many *path operations***.

## To `async` or not to `async` { #to-async-or-not-to-async }

As dependencies will also be called by **FastAPI** (the same as your *path operation functions*), the same rules apply while defining your functions.

# Path Parameters and Numeric Validations { #path-parameters-and-numeric-validations }

In the same way that you can declare more validations and metadata for query parameters with `Query`, you can declare the same type of validations and metadata for path parameters with `Path`.

## Import `Path` { #import-path }

First, import `Path` from `fastapi`, and import `Annotated`:

{* ../../docs_src/path_params_numeric_validations/tutorial001_an_py310.py hl[1,3] *}

///

And we are using this model to declare our input and the same model to declare our output:

{* ../../docs_src/response_model/tutorial002_py310.py hl[16] *}

Now, whenever a browser is creating a user with a password, the API will return the same password in the response.

In this case, it might not be a problem, because it's the same user sending the password.

"Hashing" means converting some content (a password in this case) into a sequence of bytes (just a string) that looks like gibberish.

Whenever you pass exactly the same content (exactly the same password) you get exactly the same gibberish.

But you cannot convert from the gibberish back to the password.

### Why use password hashing { #why-use-password-hashing }

### Testing file { #testing-file }

Then you could have a file `test_main.py` with your tests. It could live on the same Python package (the same directory with a `__init__.py` file):

``` hl_lines="5"
.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

Because this file is in the same package, you can use relative imports to import the object `app` from the `main` module (`main.py`):

If the passwords don't match, we return the same error.

#### Password hashing { #password-hashing }

"Hashing" means: converting some content (a password in this case) into a sequence of bytes (just a string) that looks like gibberish.

Whenever you pass exactly the same content (exactly the same password) you get exactly the same gibberish.

But you cannot convert from the gibberish back to the password.

And these same full-stack generators were the base of the [**FastAPI** Project Generators](project-generation.md).

/// info

Flask-apispec was created by the same Marshmallow developers.

///

/// check | Inspired **FastAPI** to

Generate the OpenAPI schema automatically, from the same code that defines serialization and validation.

///