Update app.py

app.py

@@ -1,6 +1,8 @@
 from fastapi import FastAPI, HTTPException
-from typing import Optional, List 
+from typing import Optional, List
 from pydantic import BaseModel
+import csv
+import os
 
 app = FastAPI()
 # 1 Define blueprint 
@@ -11,33 +13,80 @@ class Customer(BaseModel):
     phone: Optional[str]=None
     address: Optional[str]=None
 
-# 2 Create API endpoint
-customer_list =[]
+# 2 CSV Database Configuration
+CSV_FILE = "/tmp/customers.csv" if os.path.exists("/tmp") else "customers.csv"
+CSV_HEADERS = ["id", "name", "email", "phone", "address"]
+
+def initialize_csv():
+    """Initialize CSV file with headers if it doesn't exist"""
+    if not os.path.exists(CSV_FILE):
+        with open(CSV_FILE, 'w', newline='', encoding='utf-8') as file:
+            writer = csv.writer(file)
+            writer.writerow(CSV_HEADERS)
+
+def read_customers_from_csv() -> List[Customer]:
+    """Read all customers from CSV file"""
+    customers = []
+    if os.path.exists(CSV_FILE):
+        with open(CSV_FILE, 'r', newline='', encoding='utf-8') as file:
+            reader = csv.DictReader(file)
+            for row in reader:
+                customers.append(Customer(
+                    id=int(row['id']),
+                    name=row['name'],
+                    email=row['email'],
+                    phone=row['phone'] if row['phone'] else None,
+                    address=row['address'] if row['address'] else None
+                ))
+    return customers
+
+def write_customers_to_csv(customers: List[Customer]):
+    """Write all customers to CSV file"""
+    with open(CSV_FILE, 'w', newline='', encoding='utf-8') as file:
+        writer = csv.writer(file)
+        writer.writerow(CSV_HEADERS)
+        for customer in customers:
+            writer.writerow([
+                customer.id,
+                customer.name,
+                customer.email,
+                customer.phone or "",
+                customer.address or ""
+            ])
+
+# Initialize CSV file on startup
+initialize_csv()
 #Create
 @app.post("/Customer",response_model=Customer)
 def create_customer(customer: Customer):
-    customer_list.append(customer)
+    customers = read_customers_from_csv()
+    customers.append(customer)
+    write_customers_to_csv(customers)
     return customer
 
 #Read
 @app.get("/Customer",response_model=List[Customer])
 def get_customer():
-    return customer_list
+    return read_customers_from_csv()
 
 #Update
 @app.put("/Customer/{id}",response_model=Customer)
 def update_customer(id:int, customer:Customer):
-    for i,existing_customer in enumerate(customer_list):
+    customers = read_customers_from_csv()
+    for i, existing_customer in enumerate(customers):
         if existing_customer.id == id:
-            customer_list[i]=customer
+            customers[i] = customer
+            write_customers_to_csv(customers)
             return customer
-    raise HTTPException(status_code = 404, detail="customer not found")
+    raise HTTPException(status_code=404, detail="customer not found")
 
-#Delete 
+#Delete
 @app.delete("/Customer/{id}",response_model=Customer)
 def delete_customer(id:int):
-    for i,Customer in enumerate(customer_list):
-        if Customer.id == id:
-            deleted_customer=customer_list.pop(i)
+    customers = read_customers_from_csv()
+    for i, customer_obj in enumerate(customers):
+        if customer_obj.id == id:
+            deleted_customer = customers.pop(i)
+            write_customers_to_csv(customers)
             return deleted_customer
-    raise HTTPException(status_code = 404, detail="customer not found")
+    raise HTTPException(status_code=404, detail="customer not found")