Merge pull request #3868 from freqtrade/fix/3865

bittrex fetch_orderbook API change.

config.json.example

@@ -5,15 +5,15 @@
     "tradable_balance_ratio": 0.99,
     "fiat_display_currency": "USD",
     "timeframe": "5m",
-    "dry_run": false,
+    "dry_run": true,
     "cancel_open_orders_on_exit": false,
     "unfilledtimeout": {
         "buy": 10,
         "sell": 30
     },
     "bid_strategy": {
-        "ask_last_balance": 0.0,
         "use_order_book": false,
+        "ask_last_balance": 0.0,
         "order_book_top": 1,
         "check_depth_of_market": {
             "enabled": false,

config_full.json.example

@@ -7,7 +7,7 @@
     "amount_reserve_percent": 0.05,
     "amend_last_stake_amount": false,
     "last_stake_amount_min_ratio": 0.5,
-    "dry_run": false,
+    "dry_run": true,
     "cancel_open_orders_on_exit": false,
     "timeframe": "5m",
     "trailing_stop": false,

config_kraken.json.example

@@ -27,12 +27,11 @@
         "use_sell_signal": true,
         "sell_profit_only": false,
         "ignore_roi_if_buy_signal": false
-
     },
     "exchange": {
         "name": "kraken",
-        "key": "",
-        "secret": "",
+        "key": "your_exchange_key",
+        "secret": "your_exchange_key",
         "ccxt_config": {"enableRateLimit": true},
         "ccxt_async_config": {
             "enableRateLimit": true,

freqtrade/exchange/__init__.py

@@ -5,6 +5,7 @@ from freqtrade.exchange.exchange import Exchange
 # isort: on
 from freqtrade.exchange.bibox import Bibox
 from freqtrade.exchange.binance import Binance
+from freqtrade.exchange.bittrex import Bittrex
 from freqtrade.exchange.exchange import (available_exchanges, ccxt_exchanges,
                                          get_exchange_bad_reason, is_exchange_bad,
                                          is_exchange_known_ccxt, is_exchange_officially_supported,

freqtrade/exchange/binance.py

@@ -20,20 +20,9 @@ class Binance(Exchange):
         "order_time_in_force": ['gtc', 'fok', 'ioc'],
         "trades_pagination": "id",
         "trades_pagination_arg": "fromId",
+        "l2_limit_range": [5, 10, 20, 50, 100, 500, 1000],
     }
 
-    def fetch_l2_order_book(self, pair: str, limit: int = 100) -> dict:
-        """
-        get order book level 2 from exchange
-
-        20180619: binance support limits but only on specific range
-        """
-        limit_range = [5, 10, 20, 50, 100, 500, 1000]
-        # get next-higher step in the limit_range list
-        limit = min(list(filter(lambda x: limit <= x, limit_range)))
-
-        return super().fetch_l2_order_book(pair, limit)
-
     def stoploss_adjust(self, stop_loss: float, order: Dict) -> bool:
         """
         Verify stop_loss against stoploss-order value (limit or price)

freqtrade/exchange/bittrex.py

@@ -0,0 +1,23 @@
+""" Bittrex exchange subclass """
+import logging
+from typing import Dict
+
+from freqtrade.exchange import Exchange
+
+
+logger = logging.getLogger(__name__)
+
+
+class Bittrex(Exchange):
+    """
+    Bittrex exchange class. Contains adjustments needed for Freqtrade to work
+    with this exchange.
+
+    Please note that this exchange is not included in the list of exchanges
+    officially supported by the Freqtrade development team. So some features
+    may still not work as expected.
+    """
+
+    _ft_has: Dict = {
+        "l2_limit_range": [1, 25, 500],
+    }

freqtrade/exchange/exchange.py

@@ -53,7 +53,7 @@ class Exchange:
         "ohlcv_partial_candle": True,
         "trades_pagination": "time",  # Possible are "time" or "id"
         "trades_pagination_arg": "since",
-
+        "l2_limit_range": None,
     }
     _ft_has: Dict = {}
 
@@ -1069,6 +1069,16 @@ class Exchange:
             return self.fetch_stoploss_order(order_id, pair)
         return self.fetch_order(order_id, pair)
 
+    @staticmethod
+    def get_next_limit_in_list(limit: int, limit_range: Optional[List[int]]):
+        """
+        Get next greater value in the list.
+        Used by fetch_l2_order_book if the api only supports a limited range
+        """
+        if not limit_range:
+            return limit
+        return min([x for x in limit_range if limit <= x] + [max(limit_range)])
+
     @retrier
     def fetch_l2_order_book(self, pair: str, limit: int = 100) -> dict:
         """
@@ -1077,9 +1087,10 @@ class Exchange:
         Returns a dict in the format
         {'asks': [price, volume], 'bids': [price, volume]}
         """
+        limit1 = self.get_next_limit_in_list(limit, self._ft_has['l2_limit_range'])
         try:
 
-            return self._api.fetch_l2_order_book(pair, limit)
+            return self._api.fetch_l2_order_book(pair, limit1)
         except ccxt.NotSupported as e:
             raise OperationalException(
                 f'Exchange {self._api.name} does not support fetching order book.'

tests/data/test_dataprovider.py

@@ -132,7 +132,7 @@ def test_orderbook(mocker, default_conf, order_book_l2):
     res = dp.orderbook('ETH/BTC', 5)
     assert order_book_l2.call_count == 1
     assert order_book_l2.call_args_list[0][0][0] == 'ETH/BTC'
-    assert order_book_l2.call_args_list[0][0][1] == 5
+    assert order_book_l2.call_args_list[0][0][1] >= 5
 
     assert type(res) is dict
     assert 'bids' in res

tests/exchange/test_exchange.py

@@ -11,7 +11,7 @@ from pandas import DataFrame
 
 from freqtrade.exceptions import (DDosProtection, DependencyException, InvalidOrderException,
                                   OperationalException, TemporaryError)
-from freqtrade.exchange import Binance, Exchange, Kraken
+from freqtrade.exchange import Binance, Bittrex, Exchange, Kraken
 from freqtrade.exchange.common import (API_FETCH_ORDER_RETRY_COUNT, API_RETRY_COUNT,
                                        calculate_backoff)
 from freqtrade.exchange.exchange import (market_is_active, timeframe_to_minutes, timeframe_to_msecs,
@@ -148,11 +148,19 @@ def test_exchange_resolver(default_conf, mocker, caplog):
     mocker.patch('freqtrade.exchange.Exchange.validate_pairs')
     mocker.patch('freqtrade.exchange.Exchange.validate_timeframes')
     mocker.patch('freqtrade.exchange.Exchange.validate_stakecurrency')
-    exchange = ExchangeResolver.load_exchange('Bittrex', default_conf)
+
+    exchange = ExchangeResolver.load_exchange('huobi', default_conf)
     assert isinstance(exchange, Exchange)
     assert log_has_re(r"No .* specific subclass found. Using the generic class instead.", caplog)
     caplog.clear()
 
+    exchange = ExchangeResolver.load_exchange('Bittrex', default_conf)
+    assert isinstance(exchange, Exchange)
+    assert isinstance(exchange, Bittrex)
+    assert not log_has_re(r"No .* specific subclass found. Using the generic class instead.",
+                          caplog)
+    caplog.clear()
+
     exchange = ExchangeResolver.load_exchange('kraken', default_conf)
     assert isinstance(exchange, Exchange)
     assert isinstance(exchange, Kraken)
@@ -1438,6 +1446,27 @@ def test_refresh_latest_ohlcv_inv_result(default_conf, mocker, caplog):
     assert log_has("Async code raised an exception: TypeError", caplog)
 
 
+def test_get_next_limit_in_list():
+    limit_range = [5, 10, 20, 50, 100, 500, 1000]
+    assert Exchange.get_next_limit_in_list(1, limit_range) == 5
+    assert Exchange.get_next_limit_in_list(5, limit_range) == 5
+    assert Exchange.get_next_limit_in_list(6, limit_range) == 10
+    assert Exchange.get_next_limit_in_list(9, limit_range) == 10
+    assert Exchange.get_next_limit_in_list(10, limit_range) == 10
+    assert Exchange.get_next_limit_in_list(11, limit_range) == 20
+    assert Exchange.get_next_limit_in_list(19, limit_range) == 20
+    assert Exchange.get_next_limit_in_list(21, limit_range) == 50
+    assert Exchange.get_next_limit_in_list(51, limit_range) == 100
+    assert Exchange.get_next_limit_in_list(1000, limit_range) == 1000
+    # Going over the limit ...
+    assert Exchange.get_next_limit_in_list(1001, limit_range) == 1000
+    assert Exchange.get_next_limit_in_list(2000, limit_range) == 1000
+
+    assert Exchange.get_next_limit_in_list(21, None) == 21
+    assert Exchange.get_next_limit_in_list(100, None) == 100
+    assert Exchange.get_next_limit_in_list(1000, None) == 1000
+
+
 @pytest.mark.parametrize("exchange_name", EXCHANGES)
 def test_fetch_l2_order_book(default_conf, mocker, order_book_l2, exchange_name):
     default_conf['exchange']['name'] = exchange_name
@@ -1450,6 +1479,19 @@ def test_fetch_l2_order_book(default_conf, mocker, order_book_l2, exchange_name)
     assert 'asks' in order_book
     assert len(order_book['bids']) == 10
     assert len(order_book['asks']) == 10
+    assert api_mock.fetch_l2_order_book.call_args_list[0][0][0] == 'ETH/BTC'
+
+    for val in [1, 5, 10, 12, 20, 50, 100]:
+        api_mock.fetch_l2_order_book.reset_mock()
+
+        order_book = exchange.fetch_l2_order_book(pair='ETH/BTC', limit=val)
+        assert api_mock.fetch_l2_order_book.call_args_list[0][0][0] == 'ETH/BTC'
+        # Not all exchanges support all limits for orderbook
+        if not exchange._ft_has['l2_limit_range'] or val in exchange._ft_has['l2_limit_range']:
+            assert api_mock.fetch_l2_order_book.call_args_list[0][0][1] == val
+        else:
+            next_limit = exchange.get_next_limit_in_list(val, exchange._ft_has['l2_limit_range'])
+            assert api_mock.fetch_l2_order_book.call_args_list[0][0][1] == next_limit
 
 
 @pytest.mark.parametrize("exchange_name", EXCHANGES)