add one to many relationships and various updates surrounding this

class_account.py

@@ -2,6 +2,8 @@
 # Banking System Account Class
 
 from sqlalchemy import ForeignKey, Column, String, Integer, Boolean
+from sqlalchemy.orm import relationship
+
 
 
 from class_base import Base
@@ -9,23 +11,25 @@ from class_base import Base
 class Account(Base):
     __tablename__ = 'accounts'
     account_id = Column("account_id", String, primary_key=True)
+    client_id = Column(String, ForeignKey('clients.client_id'))
     description = Column("description", String)
     open_timestamp = Column("open_timestamp", String)
     account_type = Column("account_type", String)
     balance = Column("balance", Integer)
     enabled = Column("enabled", Boolean)
     notes = Column("notes", String)
-    transactions = ("transactions", String, ForeignKey("transactions.transaction_id"))
+    transactions = relationship("Transaction", backref="account")
                     
-    def __init__(self, account_id, description, open_timestamp, account_type, balance, enabled, notes, transactions):
+    def __init__(self, account_id, client_id, description, open_timestamp, account_type, balance, enabled, notes, transactions):
         self.account_id = account_id
+        self.client_id = client_id
         self.description = description
         self.open_timestamp = open_timestamp
         self.account_type = account_type
         self.balance = balance
         self.enabled = enabled
         self.notes = notes
-        self.transactions = transactions
+        self.transactions = transactions if transactions is not None else []
 
     def __repr__(self):
         return f"Account ID: {self.account_id}, Description: {self.description}, Open Timestamp: {self.open_timestamp}, Account Type: {self.account_type}, Balance: {self.balance}, Enabled: {self.enabled}, Notes: {self.notes}, Transactions: {self.transactions}"