added py script for validation

surnames.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+"""
+Fast DBLP Surname Extractor - Optimized for 4GB+ files
+"""
+
+import sys
+import re
+from collections import defaultdict
+
+
+def fast_extract_surnames(input_stream, min_count=10000):
+    """Memory-efficient surname extraction"""
+    surname_counts = defaultdict(int)
+
+    # Compile regex for performance
+    tag_pattern = re.compile(r"<(author|editor)[^>]*>([^<]+)</(author|editor)>")
+    year_pattern = re.compile(r"\s+\d{4}$")
+    entity_pattern = re.compile(r"&[^;]*;")
+
+    for line in input_stream:
+        for match in tag_pattern.finditer(line):
+            content = match.group(2).strip()
+
+            # Remove year suffix
+            content = year_pattern.sub("", content)
+
+            # Get surname (last word)
+            words = content.split()
+            if words:
+                surname = words[-1]
+                # Clean entities
+                surname = entity_pattern.sub("", surname)
+                if surname:
+                    surname_counts[surname] += 1
+
+    # Filter and sort results
+    results = [
+        (surname, count)
+        for surname, count in surname_counts.items()
+        if count >= min_count
+    ]
+    results.sort(key=lambda x: x[1], reverse=True)
+
+    return results
+
+
+def main():
+    min_count = (
+        int(sys.argv[1]) if len(sys.argv) > 1 and sys.argv[1].isdigit() else 10000
+    )
+
+    if len(sys.argv) > 1 and not sys.argv[1].isdigit():
+        # Read from file
+        with open(sys.argv[1], "r", encoding="utf-8") as f:
+            results = fast_extract_surnames(f, min_count)
+    else:
+        # Read from stdin
+        results = fast_extract_surnames(sys.stdin, min_count)
+
+    for surname, count in results:
+        print(f"{surname} {count}")
+
+
+if __name__ == "__main__":
+    main()