pkg syscall (windows-amd64), type ProcessEntry32 struct, Threads uint32
pkg syscall (windows-amd64), type ProcessEntry32 struct, Usage uint32

# CL 127740043 os: make SameFile handle paths like c:a.txt properly, Alex Brainman <******@****.***>
pkg syscall (windows-386), func FullPath(string) (string, error)
pkg syscall (windows-amd64), func FullPath(string) (string, error)

For example, you could use it to read and verify passwords generated by another system (like Django) but hash any new passwords with a different algorithm like Bcrypt.

And be compatible with all of them at the same time.

///

Create a utility function to hash a password coming from the user.

///

## Multiple body parameters { #multiple-body-parameters }

In the previous example, the *path operations* would expect a JSON body with the attributes of an `Item`, like:

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2
}
```

But you can also declare multiple body parameters, e.g. `item` and `user`:

	}

	if name != "groupby" || total != 60 {
		t.Errorf("name should be groupby, but got %v, total should be 60, but got %v", name, total)
	}

	if err := DB.Model(&User{}).Select("name, sum(age) as total").Where("name LIKE ?", "groupby%").Group("name").Having("name = ?", "groupby1").Row().Scan(&name, &total); err != nil {
		t.Errorf("no error should happen, but got %v", err)
	}

	if name != "groupby1" || total != 660 {

In many cases your application could need some external settings or configurations, for example secret keys, database credentials, credentials for email services, etc.

Most of these settings are variable (can change), like database URLs. And many could be sensitive, like secrets.

For this reason it's common to provide them in environment variables that are read by the application.

/// tip

# JSON Compatible Encoder { #json-compatible-encoder }

There are some cases where you might need to convert a data type (like a Pydantic model) to something compatible with JSON (like a `dict`, `list`, etc).

For example, if you need to store it in a database.

For that, **FastAPI** provides a `jsonable_encoder()` function.

## Using the `jsonable_encoder` { #using-the-jsonable-encoder }

This code won't be executed in your app, we only need it to *document* how that *external API* should look like.

But, you already know how to easily create automatic documentation for an API with **FastAPI**.

So we are going to use that same knowledge to document how the *external API* should look like... by creating the *path operation(s)* that the external API should implement (the ones your API will call).

/// tip

In your client you will get a JSON response like:

```JSON
{
  "model_name": "alexnet",
  "message": "Deep Learning FTW!"
}
```

## Path parameters containing paths { #path-parameters-containing-paths }

Let's say you have a *path operation* with a path `/files/{file_path}`.

But you need `file_path` itself to contain a *path*, like `home/johndoe/myfile.txt`.

	Gt(lte).Build(builder)
}

// Like whether string matches regular expression
type Like Eq

func (like Like) Build(builder Builder) {
	builder.WriteQuoted(like.Column)
	builder.WriteString(" LIKE ")
	builder.AddVar(builder, like.Value)
}

func (like Like) NegationBuild(builder Builder) {
	builder.WriteQuoted(like.Column)
	builder.WriteString(" NOT LIKE ")
	builder.AddVar(builder, like.Value)
}

{* ../../docs_src/header_params/tutorial003_an_py310.py hl[9] *}

If you communicate with that *path operation* sending two HTTP headers like:

```
X-Token: foo
X-Token: bar
```

The response would be like:

```JSON
{
    "X-Token values": [
        "bar",
        "foo"
    ]
}
```

## Recap { #recap }