fix: resolve CI failures - ccxtstore staticmethod, async tests, optimization multiprocessing

- ccxtstore.py: move retry from @staticmethod to module-level _ccxt_retry()
  to fix 'staticmethod object is not callable' on Python 3.10+ Windows
- setup.py: add pytest-asyncio to dev dependencies
- pytest.ini: add asyncio_mode = auto for async test support
- test_strategy.py/v2/test_improved_examples.py: use maxcpus=1 in
  optstrategy tests to avoid multiprocessing pickle errors in CI

Author: cloudQuant

backtrader/stores/ccxtstore.py

@@ -30,6 +30,39 @@
 
 logger = logging.getLogger(__name__)
 
+
+def _ccxt_retry(method):
+    """Module-level retry decorator for CCXTStore methods."""
+
+    @wraps(method)
+    def retry_method(self, *args, **kwargs):
+        for i in range(self.retries):
+            if self.debug:
+                logger.debug("%s - %s - Attempt %d", datetime.now(), method.__name__, i)
+
+            if self._rate_limiter:
+                self._rate_limiter.acquire()
+            else:
+                time.sleep(self.exchange.rateLimit / 1000)
+
+            try:
+                result = method(self, *args, **kwargs)
+                if self._rate_limiter and hasattr(self._rate_limiter, "on_success"):
+                    self._rate_limiter.on_success()
+                if self._connection_manager:
+                    self._connection_manager.mark_success()
+                return result
+            except (NetworkError, ExchangeError) as e:
+                if self._rate_limiter and hasattr(self._rate_limiter, "on_rate_limit_error"):
+                    if "rate" in str(e).lower() or "429" in str(e):
+                        self._rate_limiter.on_rate_limit_error()
+                if self._connection_manager:
+                    self._connection_manager.mark_failure()
+                if i == self.retries - 1:
+                    raise
+
+    return retry_method
+
 # TimeFrame constants to avoid circular import with backtrader
 # Values match backtrader.dataseries.TimeFrame
 _TF_MINUTES = 4
@@ -239,43 +272,7 @@ def get_granularity(self, timeframe, compression):
 
         return granularity
 
-    @staticmethod
-    def retry(method):
-        """Decorator for retry with rate limiting."""
-
-        @wraps(method)
-        def retry_method(self, *args, **kwargs):
-            for i in range(self.retries):
-                if self.debug:
-                    logger.debug("%s - %s - Attempt %d", datetime.now(), method.__name__, i)
-
-                # Use rate limiter if available, otherwise fall back to basic sleep
-                if self._rate_limiter:
-                    self._rate_limiter.acquire()
-                else:
-                    time.sleep(self.exchange.rateLimit / 1000)
-
-                try:
-                    result = method(self, *args, **kwargs)
-                    # Mark success for adaptive rate limiter
-                    if self._rate_limiter and hasattr(self._rate_limiter, "on_success"):
-                        self._rate_limiter.on_success()
-                    if self._connection_manager:
-                        self._connection_manager.mark_success()
-                    return result
-                except (NetworkError, ExchangeError) as e:
-                    # Mark failure for adaptive rate limiter
-                    if self._rate_limiter and hasattr(self._rate_limiter, "on_rate_limit_error"):
-                        if "rate" in str(e).lower() or "429" in str(e):
-                            self._rate_limiter.on_rate_limit_error()
-                    if self._connection_manager:
-                        self._connection_manager.mark_failure()
-                    if i == self.retries - 1:
-                        raise
-
-        return retry_method
-
-    @retry
+    @_ccxt_retry
     def get_wallet_balance(self, params=None):
         """Fetch the wallet balance from the exchange.
 
@@ -290,7 +287,7 @@ def get_wallet_balance(self, params=None):
         balance = self.exchange.fetch_balance(params)
         return balance
 
-    @retry
+    @_ccxt_retry
     def get_balance(self):
         """Fetch and update the current balance from the exchange.
 
@@ -305,7 +302,7 @@ def get_balance(self):
         self._cash = cash if cash else 0
         self._value = value if value else 0
 
-    @retry
+    @_ccxt_retry
     def getposition(self):
         """Get the current position value.
 
@@ -314,7 +311,7 @@ def getposition(self):
         """
         return self._value
 
-    @retry
+    @_ccxt_retry
     def create_order(self, symbol, order_type, side, amount, price, params):
         """Create an order on the exchange.
 
@@ -334,7 +331,7 @@ def create_order(self, symbol, order_type, side, amount, price, params):
             symbol=symbol, type=order_type, side=side, amount=amount, price=price, params=params
         )
 
-    @retry
+    @_ccxt_retry
     def cancel_order(self, order_id, symbol):
         """Cancel an existing order on the exchange.
 
@@ -347,7 +344,7 @@ def cancel_order(self, order_id, symbol):
         """
         return self.exchange.cancel_order(order_id, symbol)
 
-    @retry
+    @_ccxt_retry
     def fetch_trades(self, symbol):
         """Fetch recent trades for a symbol from the exchange.
 
@@ -359,7 +356,7 @@ def fetch_trades(self, symbol):
         """
         return self.exchange.fetch_trades(symbol)
 
-    @retry
+    @_ccxt_retry
     def fetch_ohlcv(self, symbol, timeframe, since, limit, params=None):
         """Fetch OHLCV (candlestick) data from the exchange.
 
@@ -382,7 +379,7 @@ def fetch_ohlcv(self, symbol, timeframe, since, limit, params=None):
             symbol, timeframe=timeframe, since=since, limit=limit, params=params
         )
 
-    @retry
+    @_ccxt_retry
     def fetch_order(self, oid, symbol):
         """Fetch details of a specific order from the exchange.
 
@@ -395,7 +392,7 @@ def fetch_order(self, oid, symbol):
         """
         return self.exchange.fetch_order(oid, symbol)
 
-    @retry
+    @_ccxt_retry
     def fetch_open_orders(self):
         """Fetch all open orders from the exchange.
 
@@ -404,7 +401,7 @@ def fetch_open_orders(self):
         """
         return self.exchange.fetchOpenOrders()
 
-    @retry
+    @_ccxt_retry
     def private_end_point(self, type, endpoint, params):
         """Call any private endpoint on the exchange.
 

pytest.ini

@@ -13,6 +13,7 @@ markers =
     trading: Tests that place real orders on sandbox exchange
     live: Tests that require live production environment
     slow: Tests that take a long time to execute
+asyncio_mode = auto
 filterwarnings =
     ignore::RuntimeWarning
     ignore::DeprecationWarning

setup.py

@@ -30,6 +30,7 @@
             "pytest-xdist",
             "pytest-html",
             "pytest-timeout",
+            "pytest-asyncio",
             "ruff",
             "black",
             "isort",

tests/integration/test_improved_examples.py

@@ -352,7 +352,7 @@ def test_2_3_UT_001_strategy_optimization(cerebro_with_data):
     cerebro_with_data.optstrategy(_OptSMAStrategy, period=range(10, 20, 5))
 
     # Act
-    results = cerebro_with_data.run()
+    results = cerebro_with_data.run(maxcpus=1)
 
     # Assert - Should have multiple results from optimization
     assert len(results) > 1, "Optimization should return multiple results"

tests/unit/core/test_strategy.py

@@ -246,7 +246,7 @@ def test_strategy_optimization(main=False):
     cerebro.adddata(data)
     cerebro.optstrategy(SampleStrategy1, period=range(10, 20, 5))
 
-    results = cerebro.run()
+    results = cerebro.run(maxcpus=1)
 
     if main:
         print(f"Optimization tested {len(results)} parameter combinations")

tests/unit/core/test_strategy_v2.py

@@ -216,7 +216,7 @@ def test_2_3_UT_001_strategy_optimization(cerebro_engine):
     cerebro_engine.optstrategy(SampleStrategy1, period=range(10, 20, 5))
 
     # Act
-    results = cerebro_engine.run()
+    results = cerebro_engine.run(maxcpus=1)
 
     # Assert - Should have multiple results from optimization
     assert len(results) > 1  # More than one parameter combination