Refactor datetime logging to use a single timezone variable for consistency in transaction message processing

app.py

@@ -32,6 +32,7 @@ HF_TOKEN = os.getenv("HF_TOKEN")
 GOOGLE_API_KEY = os.getenv("GOOGLE_API_KEY")
 GROQ_MODEL = "meta-llama/llama-4-scout-17b-16e-instruct"
 GOOGLE_MODEL = "gemini-2.5-flash-preview-05-20"
+ist_tz = timezone("Asia/Kolkata")
 
 class TransactionParser(BaseModel):
     """This Pydantic class is used to parse the transaction message. The message is taken and the output is structured in a specific format based upon below definitions."""
@@ -65,17 +66,17 @@ class Agent:
         self.model = model
 
     def classify_txn_type(self, state: AgentState) -> AgentState:
-        print(f"{datetime.now(timezone("Asia/Kolkata"))}: Classifying transaction type...")
+        print(f"{datetime.now(ist_tz)}: Classifying transaction type...")
         messages = state["messages"]
         if self.system:
             messages = [SystemMessage(content=self.system)] + messages
 
         message = self.model.invoke(messages)
-        print(f"{datetime.now(timezone("Asia/Kolkata"))}: Classifying transaction type completed.")
+        print(f"{datetime.now(ist_tz)}: Classifying transaction type completed.")
         return {"messages": [message]}
     
     def parse_message(self, state: AgentState) -> AgentState:
-        print(f"{datetime.now(timezone("Asia/Kolkata"))}: Parsing transaction message...")
+        print(f"{datetime.now(ist_tz)}: Parsing transaction message...")
         message = state["messages"][0]#.content
         system = """
         You are a helpful assistant skilled at parsing transaction messages and providing structured responses.
@@ -85,12 +86,12 @@ class Agent:
         prompt = ChatPromptTemplate.from_messages([("system", system), ("human", human)])
         chain = prompt | self.model.with_structured_output(TransactionParser)
         result = chain.invoke({"topic": message})
-        print(f"{datetime.now(timezone("Asia/Kolkata"))}: Parsing transaction message completed.")   
+        print(f"{datetime.now(ist_tz)}: Parsing transaction message completed.")   
         
         return {"messages": [result]}
 
     def write_message(self, state: AgentState) -> AgentState:
-        print(f"{datetime.now(timezone("Asia/Kolkata"))}: Writing transaction message to Google Sheets...")
+        print(f"{datetime.now(ist_tz)}: Writing transaction message to Google Sheets...")
         result = state["messages"][-1]
 
         SCOPES = ('https://www.googleapis.com/auth/spreadsheets', 'https://www.googleapis.com/auth/drive')
@@ -107,10 +108,10 @@ class Agent:
         wk.update_value(f'B{nrows+2}', result.dr_or_cr)
         wk.update_value(f'C{nrows+2}', result.receiver)
         wk.update_value(f'D{nrows+2}', result.category)
-        wk.update_value(f'E{nrows+2}', datetime.now(timezone("Asia/Kolkata")).strftime("%Y-%m-%d")) #result.transaction_date)
+        wk.update_value(f'E{nrows+2}', datetime.now(ist_tz).strftime("%Y-%m-%d"))
         wk.update_value(f'F{nrows+2}', result.transaction_origin)
         wk.update_value(f'G{nrows+2}', state["messages"][0])
-        print(f"{datetime.now(timezone("Asia/Kolkata"))}: Writing transaction message to Google Sheets completed.")
+        print(f"{datetime.now(ist_tz)}: Writing transaction message to Google Sheets completed.")
         return {"messages": ["Transaction Completed"]}
         
     def check_txn_and_decide(self, state: AgentState):