```Python hl_lines="2  14"
{!../../../docs_src/custom_response/tutorial007.py!}
```

#### Using `StreamingResponse` with file-like objects

If you have a file-like object (e.g. the object returned by `open()`), you can create a generator function to iterate over that file-like object.

That way, you don't have to read it all first in memory, and you can pass that generator function to the `StreamingResponse`, and return it.

endif
# The old docker issue manifests as not being able to run *any* binary. So we can test
# by trying to run a trivial program and ensuring it actually ran. If not, emit our warning.
# Note: we cannot do anything like $(shell docker version) to check, since that would also fail.
CAN_RUN := $(shell echo "can I run echo")
ifeq ($(CAN_RUN),)
$(error $(warning))
endif

#### Unwrapping a `dict` and extra keywords

And then adding the extra keyword argument `hashed_password=hashed_password`, like in:

```Python
UserInDB(**user_in.dict(), hashed_password=hashed_password)
```

...ends up being like:

```Python
UserInDB(
    username = user_dict["username"],
    password = user_dict["password"],
    email = user_dict["email"],

			}, clause.Where{
				Exprs: []clause.Expression{clause.Or(clause.Gt{Column: "score", Value: 100}, clause.Like{Column: "name", Value: "%linus%"})},
			}},
			"SELECT * FROM `users` WHERE `users`.`id` = ? AND `age` > ? OR `name` <> ? AND (`score` > ? OR `name` LIKE ?)",
			[]interface{}{"1", 18, "jinzhu", 100, "%linus%"},
		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{

    border-radius: 4px;
    padding: 75px 45px 35px;
    position: relative;
    -webkit-box-sizing: border-box;
            box-sizing: border-box;
    line-height: 1.2;
}

[data-termynal]:before {
    content: '';
    position: absolute;
    top: 15px;
    left: 15px;
    display: inline-block;
    width: 15px;
    height: 15px;
    border-radius: 50%;

    return data
        .toString()
        .split('\n')
        .filter(x => x && !x.startsWith('#'))
        .map(x => x.split("#")[0])
        .map(x => {
            const line = x.trim();
            const [path, ...owners] = line.split(/\s+/);
            return {path, owners};
        });
}

function resolveCodeowners(mapping, file) {
    let match = mapping
        .slice()
        .reverse()

Later, for your production application, you might want to use a database server like **PostgreSQL**.

!!! tip
    You could adopt ideas from the section about SQLAlchemy ORM ([SQL (Relational) Databases](../tutorial/sql-databases.md){.internal-link target=_blank}), like using utility functions to perform operations in the database, independent of your **FastAPI** code.

```console
$ pip install websockets

---> 100%
```

</div>

## WebSockets client

### In production

In your production system, you probably have a frontend created with a modern framework like React, Vue.js or Angular.

And to communicate using WebSockets with your backend you would probably use your frontend's utilities.

	// message itself contains some colored text, we needed
	// to use some ANSI control escapes to cursor color state
	// and freely move in the screen.
	for _, line := range strings.Split(errMsg, "\n") {
		if len(line) == 0 {
			// No more text to print, just quit.
			break
		}

		for {
			// Save the attributes of the current cursor helps
			// us save the text color of the passed error message

    This command will be run from the **current working directory**, the same `/code` directory you set above with `WORKDIR /code`.

!!! tip
    Review what each line does by clicking each number bubble in the code. 👆

You should now have a directory structure like:

```
.
├── app
│   ├── __init__.py
│   └── main.py