reverted back exchange.get_funding_fees method

freqtrade/exchange/exchange.py

@@ -9,7 +9,7 @@ import logging
 from copy import deepcopy
 from datetime import datetime, time, timezone
 from math import ceil
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any, Dict, List, Optional, Tuple, Union
 
 import arrow
 import ccxt
@@ -1525,6 +1525,36 @@ class Exchange:
 
         return self._api.fetch_funding_rates()
 
+    @retrier
+    def get_funding_fees(self, pair: str, since: Union[datetime, int]) -> float:
+        """
+            Returns the sum of all funding fees that were exchanged for a pair within a timeframe
+            :param pair: (e.g. ADA/USDT)
+            :param since: The earliest time of consideration for calculating funding fees,
+                in unix time or as a datetime
+        """
+
+        if not self.exchange_has("fetchFundingHistory"):
+            raise OperationalException(
+                f"fetch_funding_history() has not been implemented on ccxt.{self.name}")
+
+        if type(since) is datetime:
+            since = int(since.strftime('%s'))
+
+        try:
+            funding_history = self._api.fetch_funding_history(
+                pair=pair,
+                since=since
+            )
+            return sum(fee['amount'] for fee in funding_history)
+        except ccxt.DDoSProtection as e:
+            raise DDosProtection(e) from e
+        except (ccxt.NetworkError, ccxt.ExchangeError) as e:
+            raise TemporaryError(
+                f'Could not get funding fees due to {e.__class__.__name__}. Message: {e}') from e
+        except ccxt.BaseError as e:
+            raise OperationalException(e) from e
+
 
 def hours_to_time(hours: List[int]) -> List[time]:
     '''