cleanup_dataset.py

import os
import json
import argparse

def clean_jsonl(jsonl_path):
    """
    Reads a jsonl file, checks if referenced images exist, 
    and rewrites the file without the missing entries.
    """
    base_dir = os.path.dirname(jsonl_path)
    img_dir = os.path.join(base_dir, "images")
    
    if not os.path.exists(img_dir):
        print(f"[!] Skipping {base_dir}: 'images' folder not found.")
        return

    # Read all lines
    with open(jsonl_path, 'r', encoding='utf-8') as f:
        lines = f.readlines()

    valid_lines = []
    removed_count = 0
    total_count = len(lines)

    for line in lines:
        if not line.strip():
            continue
            
        try:
            entry = json.loads(line)
            image_name = entry.get("image")
            
            if image_name:
                image_path = os.path.join(img_dir, image_name)
                
                # THE CORE CHECK: Does the file exist?
                if os.path.exists(image_path):
                    valid_lines.append(line)
                else:
                    removed_count += 1
            else:
                # If entry has no "image" field, decide to keep or drop.
                # For this dataset format, we drop it.
                removed_count += 1
                
        except json.JSONDecodeError:
            removed_count += 1

    # Only rewrite if we actually removed something
    if removed_count > 0:
        with open(jsonl_path, 'w', encoding='utf-8') as f:
            f.writelines(valid_lines)
        print(f"[✓] Cleaned {jsonl_path}")
        print(f"    - Total Lines: {total_count}")
        print(f"    - Removed:     {removed_count}")
        print(f"    - Remaining:   {len(valid_lines)}")
    else:
        print(f"[.] No changes needed for {jsonl_path}")

def main():
    parser = argparse.ArgumentParser(description="Remove JSONL lines pointing to missing images.")
    parser.add_argument("dir", default=".", help="Root directory to scan (default: current dir).")
    args = parser.parse_args()

    print(f"[*] Scanning for data.jsonl files in '{args.dir}'...")
    
    found_files = 0
    
    # Walk through all directories recursively
    for root, dirs, files in os.walk(args.dir):
        if "data.jsonl" in files:
            found_files += 1
            full_path = os.path.join(root, "data.jsonl")
            clean_jsonl(full_path)

    if found_files == 0:
        print("[!] No 'data.jsonl' files found.")
    else:
        print("\n[*] Cleanup complete.")

if __name__ == "__main__":
    main()