refactor: Improve error handling and retries for token price API request

app_value_locked.py

@@ -238,23 +238,37 @@ def get_token_decimals(web3, token_address):
     ])
     return token_contract.functions.decimals().call()
 
-def get_token_price_usd(chain, token_address):
+def get_token_price_usd(chain, token_address, retries=3, delay=5):
+    """Fetch the USD price for a given ERC-20 token using CoinGecko API with retries and error handling."""
     chain_dict = {"optimism": "optimistic-ethereum", "base": "base", "ethereum": "ethereum"}
-    chain_name = chain_dict.get(chain, chain) 
-    time.sleep(4)
-    url = f"https://api.coingecko.com/api/v3/simple/token_price/{chain_name}?contract_addresses={token_address}&vs_currencies=usd"
-
-    headers = {
-        "accept": "application/json",
-        "x-cg-api-key": "CG-mf5xZnGELpSXeSqmHDLY2nNU"
-    }
-
-    response = requests.get(url, headers=headers)
-    data = response.json()
-
-    # Extract USD price
-    key = token_address.lower()
-    return data.get(key, {}).get('usd', None)
+    chain_name = chain_dict.get(chain, chain)
+    
+    for attempt in range(retries):
+        try:
+            time.sleep(4)  # Initial delay to avoid hitting rate limits
+            url = f"https://api.coingecko.com/api/v3/simple/token_price/{chain_name}?contract_addresses={token_address}&vs_currencies=usd"
+
+            headers = {
+                "accept": "application/json",
+                "x-cg-api-key": "CG-mf5xZnGELpSXeSqmHDLY2nNU"
+            }
+
+            response = requests.get(url, headers=headers)
+            response.raise_for_status()  # Raise an HTTPError for bad responses
+
+            data = response.json()
+
+            # Extract USD price
+            key = token_address.lower()
+            return data.get(key, {}).get('usd', None)
+
+        except requests.exceptions.RequestException as e:
+            logging.error(f"Error fetching token price for {token_address} on attempt {attempt + 1}/{retries}: {e}")
+            if attempt < retries - 1:
+                time.sleep(delay)  # Wait before retry
+            else:
+                logging.error(f"Failed to fetch token price after {retries} attempts")
+                return None  # Return None if all retry attempts fail
 
 def load_existing_transactions(file_path):
     """Load existing transactions from a CSV file."""