fix sqlalchemy session to use contextual session

main.py

@@ -53,7 +53,7 @@ class TradeThread(threading.Thread):
                     msg = 'Got {} during _process()'.format(error.__class__.__name__)
                     logger.exception(msg)
                 finally:
-                    Session().flush()
+                    Session.flush()
                     time.sleep(25)
         except (RuntimeError, JSONDecodeError):
             TelegramHandler.send_msg('*Status:* Got RuntimeError: ```\n{}\n```'.format(traceback.format_exc()))
@@ -75,7 +75,7 @@ class TradeThread(threading.Thread):
                 # Create entity and execute trade
                 trade = create_trade(float(CONFIG['stake_amount']), api_wrapper.exchange)
                 if trade:
-                    Session().add(trade)
+                    Session.add(trade)
                 else:
                     logging.info('Got no buy signal...')
             except ValueError:
@@ -134,7 +134,7 @@ def close_trade_if_fulfilled(trade: Trade) -> bool:
     # we can close this trade.
     if trade.close_profit and trade.close_date and trade.close_rate and not trade.open_order_id:
         trade.is_open = False
-        Session().flush()
+        Session.flush()
         return True
     return False
 

persistence.py

@@ -17,12 +17,13 @@ else:
     db_handle = 'sqlite:///tradesv2.sqlite'
 
 engine = create_engine(db_handle, echo=False)
-Session = scoped_session(sessionmaker(bind=engine, autoflush=True, autocommit=True))
+session = scoped_session(sessionmaker(bind=engine, autoflush=True, autocommit=True))
+Session = session()
 Base = declarative_base()
 
 class Trade(Base):
     __tablename__ = 'trades'
-    query = Session.query_property()
+    query = session.query_property()
 
     id = Column(Integer, primary_key=True)
     exchange = Column(Enum(Exchange), nullable=False)
@@ -61,7 +62,7 @@ class Trade(Base):
         self.close_profit = profit
         self.close_date = datetime.utcnow()
         self.open_order_id = order_id
-        Session().flush()
+        Session.flush()
         return profit
 
 Base.metadata.create_all(engine)

rpc/telegram.py

@@ -124,7 +124,7 @@ class TelegramHandler(object):
             profit_amounts.append((profit / 100) * trade.btc_amount)
             profits.append(profit)
 
-        bp_pair, bp_rate = Session().query(Trade.pair, func.sum(Trade.close_profit).label('profit_sum')) \
+        bp_pair, bp_rate = Session.query(Trade.pair, func.sum(Trade.close_profit).label('profit_sum')) \
             .filter(Trade.is_open.is_(False)) \
             .group_by(Trade.pair) \
             .order_by('profit_sum DESC') \
@@ -244,8 +244,7 @@ class TelegramHandler(object):
         if not get_instance().is_alive():
             TelegramHandler.send_msg('`trader is not running`', bot=bot)
             return
-
-        pair_rates = Session().query(Trade.pair, func.sum(Trade.close_profit).label('profit_sum')) \
+        pair_rates = Session.query(Trade.pair, func.sum(Trade.close_profit).label('profit_sum')) \
             .filter(Trade.is_open.is_(False)) \
             .group_by(Trade.pair) \
             .order_by('profit_sum DESC') \