if !globalCallhomeConfig.Enabled() {
		return
	}

	go func() {
		r := rand.New(rand.NewSource(time.Now().UnixNano()))
		// Leader node (that successfully acquires the lock inside runCallhome)
		// will keep performing the callhome. If the leader goes down for some reason,
		// the lock will be released and another node will acquire it and take over
		// because of this loop.
		for {

# Body - Fields

The same way you can declare additional validation and metadata in *path operation function* parameters with `Query`, `Path` and `Body`, you can declare validation and metadata inside of Pydantic models using Pydantic's `Field`.

## Import `Field`

First, you have to import it:

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[4] *}


/// warning

  env | grep ^TFCI_ > "$env_file"

  WORKING_DIR="$TFCI_GIT_DIR"
  if [[ `uname -s | grep -P '^MSYS_NT'` ]]; then
    env_file=$(cygpath -m $env_file)
    # Host dirs can only be mapped to an existing drive inside the container, so
    # T:\ is replaced with C:\.
    _TFCI_OUTPUT_DIR_WIN=$(replace_drive_letter_with_c "$TFCI_OUTPUT_DIR")
    sed -iE 's|^TFCI_OUTPUT_DIR=.*|TFCI_OUTPUT_DIR='"$_TFCI_OUTPUT_DIR_WIN"'|g' $env_file

This won't happen if you import that module (file).

So, if you have another file `importer.py` with:

```Python
from myapp import app

# Some more code
```

in that case, the automatically created variable inside of `myapp.py` will not have the variable `__name__` with a value of `"__main__"`.

So, the line:

```Python
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

will not be executed.

/// info

        raise typer.Abort()
    typer.echo("Valid README ✅")


@app.command()
def build_all() -> None:
    """
    Build mkdocs site for en, and then build each language inside, end result is located
    at directory ./site/ with each language inside.
    """
    update_languages()
    shutil.rmtree(site_path, ignore_errors=True)
    langs = [lang.name for lang in get_lang_paths() if lang.is_dir()]

You can use `async def` or normal `def`.

And you can declare dependencies with `async def` inside of normal `def` *path operation functions*, or `def` dependencies inside of `async def` *path operation functions*, etc.

It doesn't matter. **FastAPI** will know what to do.

/// note

You write standard Python with types:

```Python
from datetime import date

from pydantic import BaseModel

# Declare a variable as a str
# and get editor support inside the function
def main(user_id: str):
    return user_id


# A Pydantic model
class User(BaseModel):
    id: int
    name: str
    joined: date
```

That can then be used like:

```Python

  # $TF_VER_FULL will resolve to e.g. "2.15.0-rc2". Since $TF_VER_FULL comes
  # from get_versions.sh, which must be run *after* update_version.py, FINAL_URI
  # can't be set inside the rest of the _upload envs.
  FINAL_URI="$TFCI_ARTIFACT_FINAL_GCS_URI/$TF_VER_FULL"
  gsutil -m rsync -d -r "$DOWNLOADS" "$FINAL_URI"

  # Also mirror the latest-uploaded folder to the "latest" directory.

## Create an instance

We could create an instance of this class with:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[18] *}

And that way we are able to "parameterize" our dependency, that now has `"bar"` inside of it, as the attribute `checker.fixed_content`.

## Use the instance as a dependency

# above is tagged with "py3-none-any". We cannot change the tags by simply
# renaming the wheels as uploading to PyPI would fail with "File already exists"
# error. In order to upload to PyPI, we unpack the wheel and change the tag
# inside a metadata file to the one we want (e.g cp38-cp38-win_amd) and then
# re-pack it to generate it as a platform specific wheel with this new wheel
#tag.
python3 -m wheel unpack "${pure_python_whl}"