Improve market data fetching routines.

rstat_tool/fetcher.py

@@ -0,0 +1,46 @@
+# rstat_tool/fetcher.py
+# A dedicated, isolated script for fetching financial data.
+
+import sys
+import json
+import yfinance as yf
+import pandas as pd
+import logging
+
+# Suppress verbose yfinance logging in this isolated process
+logging.getLogger("yfinance").setLevel(logging.CRITICAL)
+
+def get_financial_data_isolated(ticker_symbol):
+    """
+    Fetches market cap and the most recent closing price for a ticker.
+    This is the robust version of the function.
+    """
+    market_cap = None
+    closing_price = None
+    try:
+        data = yf.download(
+            ticker_symbol, period="2d", progress=False, auto_adjust=False
+        )
+        if not data.empty:
+            last_close_raw = data['Close'].iloc[-1]
+            if pd.notna(last_close_raw):
+                closing_price = float(last_close_raw)
+        try:
+            market_cap = yf.Ticker(ticker_symbol).info.get('marketCap')
+        except Exception:
+            # This is a non-critical failure, we can proceed without market cap
+            pass
+        return {"market_cap": market_cap, "closing_price": closing_price}
+    except Exception:
+        # This is a critical failure, return None for both
+        return {"market_cap": None, "closing_price": None}
+
+if __name__ == "__main__":
+    if len(sys.argv) < 2:
+        # This script requires a ticker symbol as an argument
+        sys.exit(1)
+    
+    ticker_to_fetch = sys.argv[1]
+    result = get_financial_data_isolated(ticker_to_fetch)
+    # Print the result as a JSON string to standard output
+    print(json.dumps(result))