Implementation:Obss Sahi Export Cfg As Yaml

Knowledge Sources	Obss_Sahi Detectron2
Domains	Object_Detection, Configuration
Last Updated	2026-02-08 12:00 GMT

Overview

Utility function that serializes a Detectron2 configuration object to a YAML file for reuse and reproducibility.

Description

The export_cfg_as_yaml function in sahi.utils.detectron2 exports a Detectron2 CfgNode config object to YAML format. It creates the parent directory if needed and uses the built-in cfg.dump() method. The module also provides Detectron2TestConstants with predefined model zoo names for Faster R-CNN, RetinaNet, and Mask R-CNN.

Usage

Use this function when you need to persist a Detectron2 configuration to disk in YAML format, either for sharing, versioning, or later reloading the configuration without rebuilding it programmatically.

Code Reference

Source Location

• Repository: Obss_Sahi
• File: sahi/utils/detectron2.py
• Lines: 1-21

Signature

class Detectron2TestConstants:
    FASTERCNN_MODEL_ZOO_NAME = "COCO-Detection/faster_rcnn_R_50_FPN_3x.yaml"
    RETINANET_MODEL_ZOO_NAME = "COCO-Detection/retinanet_R_50_FPN_3x.yaml"
    MASKRCNN_MODEL_ZOO_NAME = "COCO-InstanceSegmentation/mask_rcnn_R_50_FPN_3x.yaml"

def export_cfg_as_yaml(cfg, export_path: str = "config.yaml") -> None:
    """Exports Detectron2 config object in yaml format.

    Args:
        cfg (detectron2.config.CfgNode): Detectron2 config object.
        export_path (str): Path to export the Detectron2 config.
    """

Import

from sahi.utils.detectron2 import export_cfg_as_yaml, Detectron2TestConstants

I/O Contract

Inputs

Name	Type	Required	Description
cfg	detectron2.config.CfgNode	Yes	Detectron2 configuration object
export_path	str	No (default "config.yaml")	File path for the exported YAML

Outputs

Name	Type	Description
YAML file	File	Detectron2 config serialized as YAML at export_path

Usage Examples

Export Detectron2 Config

from detectron2.config import get_cfg
from detectron2 import model_zoo
from sahi.utils.detectron2 import export_cfg_as_yaml

# Build config
cfg = get_cfg()
cfg.merge_from_file(model_zoo.get_config_file("COCO-Detection/faster_rcnn_R_50_FPN_3x.yaml"))
cfg.MODEL.WEIGHTS = model_zoo.get_checkpoint_url("COCO-Detection/faster_rcnn_R_50_FPN_3x.yaml")

# Export to YAML
export_cfg_as_yaml(cfg, export_path="my_config.yaml")

Related Pages

• Environment:Obss_Sahi_Python_Detection_Frameworks