fiftyone-code-style

FiftyOne Code Style

Module Template

"""
Module description.

| Copyright 2017-2026, Voxel51, Inc.
| `voxel51.com <https://voxel51.com/>`_
|
"""
import logging
import os

import numpy as np

import eta.core.utils as etau

import fiftyone as fo import fiftyone.core.fields as fof import fiftyone.core.labels as fol import fiftyone.core.utils as fou

logger = logging.getLogger(name)

def public_function(arg): """Public API function.""" return _helper(arg)

def _helper(arg): """Private helper.""" return arg

## Import Organization

Four groups, alphabetized within each, separated by blank lines:

| Group | Example |
|-------|---------|
| 1. Standard library | `import logging`, `import os` |
| 2. Third-party | `import numpy as np` |
| 3. eta packages | `import eta.core.utils as etau` |
| 4. FiftyOne | `import fiftyone.core.labels as fol` |

### FiftyOne Import Aliases

| Module | Alias |
|--------|-------|
| `fiftyone` | `fo` |
| `fiftyone.core.labels` | `fol` |
| `fiftyone.core.fields` | `fof` |
| `fiftyone.core.media` | `fom` |
| `fiftyone.core.storage` | `fos` |
| `fiftyone.core.utils` | `fou` |
| `fiftyone.utils.image` | `foui` |
| `fiftyone.utils.video` | `fouv` |

## Docstrings (Google-Style)

```python
def get_operator(operator_uri, enabled=True):
    """Gets the operator with the given URI.

    Args:
        operator_uri: the operator URI
        enabled (True): whether to include only enabled operators (True) or
            only disabled operators (False) or all operators ("all")

    Returns:
        an :class:`fiftyone.operators.Operator`

    Raises:
        ValueError: if the operator is not found
    """

Key patterns:

• Args with defaults: param (default): description
• Multi-line descriptions: indent continuation
• Cross-references: :class:fiftyone.module.Class``

Lazy Imports

Use fou.lazy_import() for optional/heavy dependencies:

o3d = fou.lazy_import("open3d", callback=lambda: fou.ensure_package("open3d"))

mask_utils = fou.lazy_import(
    "pycocotools.mask", callback=lambda: fou.ensure_import("pycocotools")
)

Guard Patterns

Use hasattr() for optional attributes:

if hasattr(label, "confidence"):
    if label.confidence is None or label.confidence < threshold:
        label = label.__class__()

Error Handling

Use logger.warning() for non-fatal errors:

try:
    result = process_data(data)
except Exception as e:
    logger.warning("Failed to process data: %s", e)

Avoid Redundant Code

Before writing new functions, search for existing implementations:

• Local: search the FiftyOne source if available in the environment
• Remote: search https://github.com/voxel51/fiftyone
• Check fiftyone/core/utils.py and fiftyone/utils/* first

Common Utilities

Module	Functions
fou	lazy_import(), ensure_package(), extract_kwargs_for_class()
etau	guess_mime_type(), ensure_dir(), make_temp_dir()

Quick Reference

Pattern	Convention
Module structure	Docstring → imports → logger → public → private
Private functions	_prefix
Docstrings	Google-style with Args/Returns/Raises
Error handling	logger.warning() for non-fatal
Lazy imports	fou.lazy_import() for optional deps
Guard patterns	hasattr() checks
Import aliases	fo, fol, fof, fom, fos, fou