Add spreadsheet diff by designator

Co-authored-by: Cursor <cursoragent@cursor.com>

diff_spreadsheets.py

@@ -0,0 +1,122 @@
+#!/usr/bin/env python3
+"""
+Diff two spreadsheets by designator column. Data starts at row 10 by default.
+
+Usage:
+  python3 diff_spreadsheets.py file1.xlsx file2.xlsx [-o output.json]
+  python3 diff_spreadsheets.py   # uses SHEET1, SHEET2, DIFF_OUTPUT from .env
+
+All paths and options: use .env or CLI; CLI overrides .env.
+"""
+
+import argparse
+import json
+import os
+import sys
+from pathlib import Path
+
+try:
+    from dotenv import load_dotenv
+    load_dotenv()
+except ImportError:
+    pass
+
+try:
+    import pandas as pd
+except ImportError:
+    print("Install pandas and openpyxl: pip install pandas openpyxl", file=sys.stderr)
+    sys.exit(1)
+
+
+def read_designators(path: str, designator_col: int = 0, start_row: int = 9) -> set[str]:
+    """Load spreadsheet and return set of designator values from the given column, starting at start_row (0-based; 9 = row 10)."""
+    p = Path(path)
+    if not p.exists():
+        raise FileNotFoundError(path)
+    suffix = p.suffix.lower()
+    if suffix in (".xlsx", ".xls"):
+        df = pd.read_excel(path, header=None, engine="openpyxl" if suffix == ".xlsx" else None)
+    elif suffix == ".csv":
+        df = pd.read_csv(path, header=None)
+    else:
+        raise ValueError(f"Unsupported format: {suffix}")
+    if designator_col >= df.shape[1]:
+        raise ValueError(f"Column {designator_col} not in sheet (has {df.shape[1]} columns)")
+    # from start_row to end, take the designator column, drop NaN, strip strings
+    col = df.iloc[start_row:, designator_col]
+    values = set()
+    for v in col:
+        if pd.isna(v):
+            continue
+        s = str(v).strip()
+        if s:
+            values.add(s)
+    return values
+
+
+def main() -> int:
+    default1 = os.environ.get("SHEET1", "").strip() or None
+    default2 = os.environ.get("SHEET2", "").strip() or None
+    default_out = os.environ.get("DIFF_OUTPUT", "").strip() or "output/spreadsheet_diff.json"
+    default_col = os.environ.get("DESIGNATOR_COL", "").strip()
+    default_start = os.environ.get("START_ROW", "").strip()
+    try:
+        default_col = int(default_col) if default_col else 0
+    except ValueError:
+        default_col = 0
+    try:
+        default_start = int(default_start) if default_start else 9
+    except ValueError:
+        default_start = 9
+
+    parser = argparse.ArgumentParser(description="Diff two spreadsheets by designator column")
+    parser.add_argument("file1", nargs="?", default=default1, help="First spreadsheet (default: SHEET1 from .env)")
+    parser.add_argument("file2", nargs="?", default=default2, help="Second spreadsheet (default: SHEET2 from .env)")
+    parser.add_argument("-o", "--output", default=default_out, help="Output JSON (default: DIFF_OUTPUT from .env)")
+    parser.add_argument("--designator-col", type=int, default=default_col, help="Designator column 0-based (default: DESIGNATOR_COL from .env or 0)")
+    parser.add_argument("--start-row", type=int, default=default_start, help="First data row 0-based, 9=row 10 (default: START_ROW from .env or 9)")
+    args = parser.parse_args()
+
+    path1 = (args.file1 or default1 or "").strip()
+    path2 = (args.file2 or default2 or "").strip()
+    if not path1 or not path2:
+        parser.error("Need two files. Set SHEET1 and SHEET2 in .env or pass two paths.")
+
+    try:
+        d1 = read_designators(path1, args.designator_col, args.start_row)
+        d2 = read_designators(path2, args.designator_col, args.start_row)
+    except Exception as e:
+        print(f"Error: {e}", file=sys.stderr)
+        return 1
+
+    only1 = sorted(d1 - d2)
+    only2 = sorted(d2 - d1)
+    both = sorted(d1 & d2)
+
+    report = {
+        "file1": path1,
+        "file2": path2,
+        "designator_col": args.designator_col,
+        "start_row": args.start_row + 1,
+        "only_in_file1": only1,
+        "only_in_file2": only2,
+        "in_both": both,
+        "count_only_in_file1": len(only1),
+        "count_only_in_file2": len(only2),
+        "count_in_both": len(both),
+    }
+
+    out_path = Path(args.output)
+    out_path.parent.mkdir(parents=True, exist_ok=True)
+    out_path.write_text(json.dumps(report, indent=2), encoding="utf-8")
+    print(f"Wrote {args.output}")
+    print(f"Only in file1: {len(only1)} | Only in file2: {len(only2)} | In both: {len(both)}")
+    if only1:
+        print("  Only in file1:", ", ".join(only1[:20]) + (" ..." if len(only1) > 20 else ""))
+    if only2:
+        print("  Only in file2:", ", ".join(only2[:20]) + (" ..." if len(only2) > 20 else ""))
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())