Update dataset_stats() for HUB

[glenn-jocher]

Cleanup of b6fdd2e

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Enhanced dataset handling with autodownload feature and simplified usage.

📊 Key Changes

• Added an autodownload parameter to the dataset_stats function for conditional dataset downloading.
• Simplified data file paths by removing the 'data/' prefix from the default path argument.
• Streamlined the process of checking dataset existence and potential automatic download within check_dataset function.

🎯 Purpose & Impact

• 🔄 Purpose: The updates are intended to give users more control over dataset downloads and streamline the developer experience when working with datasets.
• ⬇️ Impact: Users now have the option to automatically download missing datasets during stat checks, reducing manual download steps, and potential errors associated with missing data. The simplification of the file paths makes the API smoother and more user-friendly.

[glenn-jocher]

@kalenmike this is our new function for dataset statistics. Example usage on VOC (20 classes). If test split is missing then it will have a value of None.

from utils.datasets import *; dataset_stats('voc.yaml', verbose=True)

Scanning '../coco128/labels/train2017.cache' images and labels... 128 found, 0 missing, 2 empty, 0 corrupted: 100%|██████████| 128/128 [00:06<?, ?it/s]
Scanning '../VOC/labels/train.cache' images and labels... 16551 found, 0 missing, 0 empty, 0 corrupted: 100%|██████████| 16551/16551 [00:00<?, ?it/s]
Statistics: 100%|██████████| 16551/16551 [00:00<00:00, 260314.63it/s]
Scanning '../VOC/labels/val.cache' images and labels... 4952 found, 0 missing, 0 empty, 0 corrupted: 100%|██████████| 4952/4952 [00:00<?, ?it/s]
Statistics: 100%|██████████| 4952/4952 [00:00<00:00, 288326.74it/s]

The function returns a dictionary:

- nc: 20  # number of classes
  names:  # class names
  - aeroplane
  - bicycle
  - bird
  - boat
  - bottle
  - bus
  - car
  - cat
  - chair
  - cow
  - diningtable
  - dog
  - horse
  - motorbike
  - person
  - pottedplant
  - sheep
  - sofa
  - train
  - tvmonitor
  train:  # < ---  train split
    instances:
      total: 40058
      per_class:
      - 1171
      - 1064
      - 1605
      - 1140
      - 1764
      - 822
      - 3267
      - 1593
      - 3152
      - 847
      - 824
      - 2025
      - 1072
      - 1052
      - 13256
      - 1487
      - 1070
      - 814
      - 925
      - 1108
    images:
      total: 16551
      unlabelled: 0
      per_class:
      - 908
      - 795
      - 1095
      - 689
      - 950
      - 607
      - 1874
      - 1417
      - 1564
      - 444
      - 738
      - 1707
      - 769
      - 771
      - 6095
      - 772
      - 421
      - 736
      - 805
      - 831
  val:  # < --- val split
    instances:
      total: 12032
      per_class:
      - 285
      - 337
      - 459
      - 263
      - 469
      - 213
      - 1201
      - 358
      - 756
      - 244
      - 206
      - 489
      - 348
      - 325
      - 4528
      - 480
      - 242
      - 239
      - 282
      - 308
    images:
      total: 4952
      unlabelled: 0
      per_class:
      - 204
      - 239
      - 282
      - 172
      - 212
      - 174
      - 721
      - 322
      - 417
      - 127
      - 190
      - 418
      - 274
      - 222
      - 2007
      - 224
      - 97
      - 223
      - 259
      - 229
  test: null  # < --- test split

[kalenmike]

Looks good

[glenn-jocher]

@kalenmike great! PR is merged.