Refactor load_market out of validate_pairs

freqtrade/exchange/__init__.py

@@ -98,6 +98,7 @@ class Exchange(object):
 
         logger.info('Using Exchange "%s"', self.name)
 
+        self.markets = self._load_markets()
         # Check if all pairs are available
         self.validate_pairs(config['exchange']['pair_whitelist'])
 
@@ -167,6 +168,16 @@ class Exchange(object):
             logger.warning('Could not load async markets. Reason: %s', e)
             return
 
+    def _load_markets(self) -> List[str]:
+        """ Initialize markets both sync and async """
+        try:
+            markets = self._api.load_markets()
+            self._load_async_markets()
+            return markets
+        except ccxt.BaseError as e:
+            logger.warning('Unable to initialize markets. Reason: %s', e)
+        return []
+
     def validate_pairs(self, pairs: List[str]) -> None:
         """
         Checks if all given pairs are tradable on the current exchange.
@@ -175,11 +186,8 @@ class Exchange(object):
         :return: None
         """
 
-        try:
-            markets = self._api.load_markets()
-            self._load_async_markets()
-        except ccxt.BaseError as e:
-            logger.warning('Unable to validate pairs (assuming they are correct). Reason: %s', e)
+        if not self.markets:
+            logger.warning('Unable to validate pairs (assuming they are correct).')
             return
 
         stake_cur = self._conf['stake_currency']
@@ -189,7 +197,7 @@ class Exchange(object):
             if not pair.endswith(stake_cur):
                 raise OperationalException(
                     f'Pair {pair} not compatible with stake_currency: {stake_cur}')
-            if pair not in markets:
+            if pair not in self.markets:
                 raise OperationalException(
                     f'Pair {pair} is not available at {self.name}')