Refactor filter_pairlist()

freqtrade/pairlist/IPairList.py

@@ -3,6 +3,7 @@ PairList Handler base class
 """
 import logging
 from abc import ABC, abstractmethod, abstractproperty
+from copy import deepcopy
 from typing import Any, Dict, List
 
 from cachetools import TTLCache, cached
@@ -75,16 +76,40 @@ class IPairList(ABC):
         -> Please overwrite in subclasses
         """
 
-    @abstractmethod
+    def _validate_pair(self, ticker) -> bool:
+        """
+        Check one pair against Pairlist Handler's specific conditions.
+
+        Either implement it in the Pairlist Handler or override the generic
+        filter_pairlist() method.
+
+        :param ticker: ticker dict as returned from ccxt.load_markets()
+        :return: True if the pair can stay, false if it should be removed
+        """
+        raise NotImplementedError()
+
     def filter_pairlist(self, pairlist: List[str], tickers: Dict) -> List[str]:
         """
         Filters and sorts pairlist and returns the whitelist again.
+
         Called on each bot iteration - please use internal caching if necessary
-        -> Please overwrite in subclasses
+        This generic implementation calls self._validate_pair() for each pair
+        in the pairlist.
+
+        Some Pairlist Handlers override this generic implementation and employ
+        own filtration.
+
         :param pairlist: pairlist to filter or sort
         :param tickers: Tickers (from exchange.get_tickers()). May be cached.
         :return: new whitelist
         """
+        # Copy list since we're modifying this list
+        for p in deepcopy(pairlist):
+            # Filter out assets
+            if not self._validate_pair(tickers[p]):
+                pairlist.remove(p)
+
+        return pairlist
 
     def verify_blacklist(self, pairlist: List[str], logmethod) -> List[str]:
         """

freqtrade/pairlist/PrecisionFilter.py

@@ -2,8 +2,7 @@
 Precision pair list filter
 """
 import logging
-from copy import deepcopy
+from typing import Any, Dict
-from typing import Any, Dict, List
 
 from freqtrade.pairlist.IPairList import IPairList
 
@@ -36,16 +35,14 @@ class PrecisionFilter(IPairList):
         """
         return f"{self.name} - Filtering untradable pairs."
 
-    def _validate_precision_filter(self, ticker: dict, stoploss: float) -> bool:
+    def _validate_pair(self, ticker: dict) -> bool:
         """
         Check if pair has enough room to add a stoploss to avoid "unsellable" buys of very
         low value pairs.
         :param ticker: ticker dict as returned from ccxt.load_markets()
-        :param stoploss: stoploss value as set in the configuration
-                        (already cleaned to be 1 - stoploss)
         :return: True if the pair can stay, False if it should be removed
         """
-        stop_price = ticker['ask'] * stoploss
+        stop_price = ticker['ask'] * self._stoploss
 
         # Adjust stop-prices to precision
         sp = self._exchange.price_to_precision(ticker["symbol"], stop_price)
@@ -60,15 +57,3 @@ class PrecisionFilter(IPairList):
             return False
 
         return True
-
-    def filter_pairlist(self, pairlist: List[str], tickers: Dict) -> List[str]:
-        """
-        Filters and sorts pairlists and assigns and returns them again.
-        """
-        # Copy list since we're modifying this list
-        for p in deepcopy(pairlist):
-            # Filter out assets which would not allow setting a stoploss
-            if not self._validate_precision_filter(tickers[p], self._stoploss):
-                pairlist.remove(p)
-
-        return pairlist

freqtrade/pairlist/PriceFilter.py

@@ -2,8 +2,7 @@
 Price pair list filter
 """
 import logging
-from copy import deepcopy
+from typing import Any, Dict
-from typing import Any, Dict, List
 
 from freqtrade.pairlist.IPairList import IPairList
 
@@ -35,12 +34,15 @@ class PriceFilter(IPairList):
         """
         return f"{self.name} - Filtering pairs priced below {self._low_price_ratio * 100}%."
 
-    def _validate_ticker_lowprice(self, ticker) -> bool:
+    def _validate_pair(self, ticker) -> bool:
         """
         Check if if one price-step (pip) is > than a certain barrier.
         :param ticker: ticker dict as returned from ccxt.load_markets()
         :return: True if the pair can stay, false if it should be removed
         """
+        if not self._low_price_ratio:
+            return True
+
         if ticker['last'] is None:
             self.log_on_refresh(logger.info,
                                 f"Removed {ticker['symbol']} from whitelist, because "
@@ -53,20 +55,3 @@ class PriceFilter(IPairList):
                                              f"because 1 unit is {changeperc * 100:.3f}%")
             return False
         return True
-
-    def filter_pairlist(self, pairlist: List[str], tickers: Dict) -> List[str]:
-        """
-        Filters and sorts pairlist and returns the whitelist again.
-        Called on each bot iteration - please use internal caching if necessary
-        :param pairlist: pairlist to filter or sort
-        :param tickers: Tickers (from exchange.get_tickers()). May be cached.
-        :return: new whitelist
-        """
-        if self._low_price_ratio:
-            # Copy list since we're modifying this list
-            for p in deepcopy(pairlist):
-                # Filter out assets which would not allow setting a stoploss
-                if not self._validate_ticker_lowprice(tickers[p]):
-                    pairlist.remove(p)
-
-        return pairlist

freqtrade/pairlist/ShuffleFilter.py

@@ -3,7 +3,7 @@ Shuffle pair list filter
 """
 import logging
 import random
-from typing import Dict, List
+from typing import Any, Dict, List
 
 from freqtrade.pairlist.IPairList import IPairList
 
@@ -13,7 +13,8 @@ logger = logging.getLogger(__name__)
 
 class ShuffleFilter(IPairList):
 
-    def __init__(self, exchange, pairlistmanager, config, pairlistconfig: dict,
+    def __init__(self, exchange, pairlistmanager,
+                 config: Dict[str, Any], pairlistconfig: Dict[str, Any],
                  pairlist_pos: int) -> None:
         super().__init__(exchange, pairlistmanager, config, pairlistconfig, pairlist_pos)
 

freqtrade/pairlist/SpreadFilter.py

@@ -2,8 +2,7 @@
 Spread pair list filter
 """
 import logging
-from copy import deepcopy
+from typing import Any, Dict
-from typing import Dict, List
 
 from freqtrade.pairlist.IPairList import IPairList
 
@@ -13,7 +12,8 @@ logger = logging.getLogger(__name__)
 
 class SpreadFilter(IPairList):
 
-    def __init__(self, exchange, pairlistmanager, config, pairlistconfig: dict,
+    def __init__(self, exchange, pairlistmanager,
+                 config: Dict[str, Any], pairlistconfig: Dict[str, Any],
                  pairlist_pos: int) -> None:
         super().__init__(exchange, pairlistmanager, config, pairlistconfig, pairlist_pos)
 
@@ -35,7 +35,7 @@ class SpreadFilter(IPairList):
         return (f"{self.name} - Filtering pairs with ask/bid diff above "
                 f"{self._max_spread_ratio * 100}%.")
 
-    def _validate_spread(self, ticker: dict) -> bool:
+    def _validate_pair(self, ticker: dict) -> bool:
         """
         Validate spread for the ticker
         :param ticker: ticker dict as returned from ccxt.load_markets()
@@ -51,20 +51,3 @@ class SpreadFilter(IPairList):
             else:
                 return True
         return False
-
-    def filter_pairlist(self, pairlist: List[str], tickers: Dict) -> List[str]:
-        """
-        Filters and sorts pairlist and returns the whitelist again.
-        Called on each bot iteration - please use internal caching if necessary
-        :param pairlist: pairlist to filter or sort
-        :param tickers: Tickers (from exchange.get_tickers()). May be cached.
-        :return: new whitelist
-        """
-        # Copy list since we're modifying this list
-        for p in deepcopy(pairlist):
-            ticker = tickers[p]
-            # Filter out assets
-            if not self._validate_spread(ticker):
-                pairlist.remove(p)
-
-        return pairlist

freqtrade/pairlist/VolumePairList.py

@@ -19,7 +19,8 @@ SORT_VALUES = ['askVolume', 'bidVolume', 'quoteVolume']
 
 class VolumePairList(IPairList):
 
-    def __init__(self, exchange, pairlistmanager, config: Dict[str, Any], pairlistconfig: dict,
+    def __init__(self, exchange, pairlistmanager,
+                 config: Dict[str, Any], pairlistconfig: Dict[str, Any],
                  pairlist_pos: int) -> None:
         super().__init__(exchange, pairlistmanager, config, pairlistconfig, pairlist_pos)