Update app.py

app.py

@@ -168,14 +168,15 @@ async def fetch_series(
 
         # Robust Python Logic for Strike Pricing mapping 
         strike_map = {}
-        prefix = f"{root}{expiry}"
         for inst in instruments:
             if inst.endswith('CE') or inst.endswith('PE'):
                 clean_inst = inst.split(":")[-1]
-                # Safest: remove Root+Expiry then search 
-                if clean_inst.startswith(prefix):
-                    remainder = clean_inst[len(prefix):]
-                    match = re.search(r'^(\d+(?:\.\d+)?)(CE|PE)$', remainder)
+                
+                if clean_inst.startswith(root):
+                    remainder = clean_inst[len(root):]
+                    # Fyers date codes are always 5-6 characters (e.g. 26310 or 26MAR). 
+                    # By skipping the first 5 chars, we isolate the true strike perfectly.
+                    match = re.search(r'(\d+(?:\.\d+)?)(?:CE|PE)$', remainder[5:])
                     if match:
                         strike_map[inst] = float(match.group(1))
                         continue