BLD: added a coordinator script and fixed an issue with candle calculation

catalyst/exchange/ccxt/ccxt_exchange.py

@@ -1016,19 +1016,27 @@ class CCXT(Exchange):
         return result
 
     def get_trades(self, asset, my_trades=True, start_dt=None, limit=100):
-        if not my_trades:
-            raise NotImplemented(
-                'get_trades only supports "my trades"'
-            )
-
         # TODO: is it possible to sort this? Limit is useless otherwise.
         ccxt_symbol = self.get_symbol(asset)
+        if start_dt:
+            delta = start_dt - get_epoch()
+            since = int(delta.total_seconds()) * 1000
+        else:
+            since = None
+
         try:
-            trades = self.api.fetch_my_trades(
-                symbol=ccxt_symbol,
-                since=start_dt,
-                limit=limit,
-            )
+            if my_trades:
+                trades = self.api.fetch_my_trades(
+                    symbol=ccxt_symbol,
+                    since=since,
+                    limit=limit,
+                )
+            else:
+                trades = self.api.fetch_trades(
+                    symbol=ccxt_symbol,
+                    since=since,
+                    limit=limit,
+                )
         except (ExchangeError, NetworkError) as e:
             log.warn(
                 'unable to fetch trades {} / {}: {}'.format(

catalyst/exchange/utils/exchange_utils.py

@@ -1,18 +1,16 @@
 import hashlib
-import json
 import os
-import pickle
 import shutil
-from datetime import date, datetime
 
+import json
 import pandas as pd
+import pickle
 from catalyst.assets._assets import TradingPair
+from datetime import date, datetime
 from six import string_types
 from six.moves.urllib import request
 
-from catalyst.constants import DATE_FORMAT, SYMBOLS_URL
-from catalyst.exchange.exchange_errors import ExchangeSymbolsNotFound, \
-    InvalidHistoryFrequencyError, InvalidHistoryFrequencyAlias
+from catalyst.constants import EXCHANGE_CONFIG_URL
 from catalyst.exchange.utils.serialization_utils import ExchangeJSONEncoder, \
     ExchangeJSONDecoder, ConfigJSONEncoder
 from catalyst.utils.paths import data_root, ensure_directory, \
@@ -142,6 +140,7 @@ def get_exchange_config(exchange_name, filename=None, environ=None):
         except ValueError:
             return dict()
 
+
 def save_exchange_config(exchange_name, config, filename=None, environ=None):
     """
     Save assets into an exchange_config file.
@@ -690,3 +689,33 @@ def get_candles_df(candles, field, freq, bar_count, end_dt):
     df.dropna(inplace=True)
 
     return df
+
+
+def get_trades_df(trades):
+    df = pd.DataFrame(trades)
+    df.index = pd.to_datetime(df.pop('datetime'))
+    df.index = df.index.tz_localize('UTC')
+
+    return df
+
+
+def candles_from_trades(trades_df, freq):
+    """
+    Calculate OHLCV from candles.
+
+    Parameters
+    ----------
+    trades_df
+    freq
+
+    Returns
+    -------
+
+    """
+    df = trades_df['price'].resample(freq).ohlc()  # type: pd.DataFrame
+    df['volume'] = trades_df['amount'].resample(freq).sum()
+
+    df.dropna(axis=0, how='all', inplace=True)
+    df.sort_index(inplace=True, ascending=False)
+
+    return df

tests/exchange/test_ccxt.py

@@ -5,7 +5,8 @@ from catalyst.exchange.utils.stats_utils import set_print_settings
 from .base import BaseExchangeTestCase
 from catalyst.exchange.ccxt.ccxt_exchange import CCXT
 from catalyst.exchange.exchange_execution import ExchangeLimitOrder
-from catalyst.exchange.utils.exchange_utils import get_exchange_auth
+from catalyst.exchange.utils.exchange_utils import get_exchange_auth, \
+    get_trades_df, candles_from_trades
 from catalyst.finance.order import Order
 
 log = Logger('test_ccxt')
@@ -14,12 +15,13 @@ log = Logger('test_ccxt')
 class TestCCXT(BaseExchangeTestCase):
     @classmethod
     def setup(self):
-        exchange_name = 'bittrex'
+        exchange_name = 'binance'
         auth = get_exchange_auth(exchange_name)
         self.exchange = CCXT(
             exchange_name=exchange_name,
             key=auth['key'],
             secret=auth['secret'],
+            password=None,
             base_currency='usdt',
         )
         self.exchange.init()
@@ -90,6 +92,37 @@ class TestCCXT(BaseExchangeTestCase):
         assert trades
         pass
 
+    def test_validate_volume(self):
+        asset = self.exchange.get_asset('eng_eth')
+        candles = self.exchange.get_candles(
+            freq='1T',
+            assets=[asset],
+            bar_count=10,
+        )
+        df = pd.DataFrame(candles[asset])
+        df.set_index('last_traded', drop=True, inplace=True)
+
+        df.drop_duplicates()
+        df.sort_index(inplace=True, ascending=False)
+        assert candles
+
+        start_dt = df.index[-1]
+        trades = self.exchange.get_trades(
+            asset, start_dt=start_dt, my_trades=False
+        )
+        assert trades
+
+        trades_df = get_trades_df(trades)
+        df2 = candles_from_trades(trades_df, '1T')
+
+        set_print_settings()
+        log.info(
+            'comparing candles / resampled trades:\n{}\n{}'.format(
+                df, df2
+            )
+        )
+        pass
+
     def test_get_executed_order(self):
         log.info('retrieving executed order')
         asset = self.exchange.get_asset('eng_eth')