Merge pull request #3169 from freqtrade/fix_pricefilter

Fix pricefilter

freqtrade/exchange/exchange.py

@@ -452,6 +452,17 @@ class Exchange:
                 price = ceil(big_price) / pow(10, symbol_prec)
         return price
 
+    def price_get_one_pip(self, pair: str, price: float) -> float:
+        """
+        Get's the "1 pip" value for this pair.
+        Used in PriceFilter to calculate the 1pip movements.
+        """
+        precision = self.markets[pair]['precision']['price']
+        if self.precisionMode == TICK_SIZE:
+            return precision
+        else:
+            return 1 / pow(10, precision)
+
     def dry_run_order(self, pair: str, ordertype: str, side: str, amount: float,
                       rate: float, params: Dict = {}) -> Dict[str, Any]:
         order_id = f'dry_run_{side}_{randint(0, 10**6)}'

freqtrade/pairlist/PriceFilter.py

@@ -35,12 +35,10 @@ class PriceFilter(IPairList):
         """
         Check if if one price-step (pip) is > than a certain barrier.
         :param ticker: ticker dict as returned from ccxt.load_markets()
-        :param precision: Precision
         :return: True if the pair can stay, false if it should be removed
         """
-        precision = self._exchange.markets[ticker['symbol']]['precision']['price']
-
-        compare = ticker['last'] + 1 / pow(10, precision)
+        compare = ticker['last'] + self._exchange.price_get_one_pip(ticker['symbol'],
+                                                                    ticker['last'])
         changeperc = (compare - ticker['last']) / ticker['last']
         if changeperc > self._low_price_ratio:
             logger.info(f"Removed {ticker['symbol']} from whitelist, "

tests/exchange/test_exchange.py

@@ -253,6 +253,32 @@ def test_price_to_precision(default_conf, mocker, price, precision_mode, precisi
     assert pytest.approx(exchange.price_to_precision(pair, price)) == expected
 
 
+@pytest.mark.parametrize("price,precision_mode,precision,expected", [
+    (2.34559, 2, 4, 0.0001),
+    (2.34559, 2, 5, 0.00001),
+    (2.34559, 2, 3, 0.001),
+    (2.9999, 2, 3, 0.001),
+    (200.0511, 2, 3, 0.001),
+    # Tests for Tick_size
+    (2.34559, 4, 0.0001, 0.0001),
+    (2.34559, 4, 0.00001, 0.00001),
+    (2.34559, 4, 0.0025, 0.0025),
+    (2.9909, 4, 0.0025, 0.0025),
+    (234.43, 4, 0.5, 0.5),
+    (234.43, 4, 0.0025, 0.0025),
+    (234.43, 4, 0.00013, 0.00013),
+
+])
+def test_price_get_one_pip(default_conf, mocker, price, precision_mode, precision, expected):
+    markets = PropertyMock(return_value={'ETH/BTC': {'precision': {'price': precision}}})
+    exchange = get_patched_exchange(mocker, default_conf, id="binance")
+    mocker.patch('freqtrade.exchange.Exchange.markets', markets)
+    mocker.patch('freqtrade.exchange.Exchange.precisionMode',
+                 PropertyMock(return_value=precision_mode))
+    pair = 'ETH/BTC'
+    assert pytest.approx(exchange.price_get_one_pip(pair, price)) == expected
+
+
 def test_set_sandbox(default_conf, mocker):
     """
     Test working scenario