added in_memory_db practice in various scenarios

.gitignore

@@ -122,6 +122,7 @@ venv.bak/
 # Ignore text
 *.txt
 !requirements.txt
+*.json
 
 # Ignore mp3
 *.mp3

exercises/in_memory_db.py

@@ -0,0 +1,83 @@
+# The problem requires implementing an in-memory key-value store
+# where you can set a key-value pair and
+# retrieve the value of a key.
+
+# Example:
+# db.set(101, ["Sanjeev", "ProdSec"])
+# db.set(102, ["Deep", "DevSecOps"])
+# db.get(102)
+# Think of command line for n inputs, set for n inputs, then based on command implement get, delete
+# Example:
+# Choose below options for operations:
+#     1. set/create entries
+#     How many entries: 2
+#     emp_id: input
+#     emp_details: input([])
+#     2. get emp_id details
+#     3. delete emp_id details
+#     4. update emp_id details
+
+class DB:
+
+    def __init__(self):
+        self.dic = {}
+
+    def set(self, key: int, value: list) -> None:
+        if not isinstance(key, int):
+            raise TypeError("Key must be an integer")
+        if not isinstance(value, list):
+            raise TypeError("Value must be a list")
+        if key in self.dic:
+            raise ValueError(f"Key {key} already exists")
+        self.dic[key] = value
+
+    def get(self, key: int) -> list:
+        if not isinstance(key, int):
+            raise TypeError("Key must be an integer")
+        if key in self.dic:
+            return self.dic[key]
+        else:
+            print(f"No record found for emp id: {key}")
+            return None
+
+    def delete(self, key: int) -> None:
+        if not isinstance(key, int):
+            raise TypeError("Key must be an integer")
+        if key in self.dic:
+            print(f"Deleting emp id {key} details: {self.dic[key]}")
+            del self.dic[key]
+            print(f"Emp id {key} deleted successfully.")
+        else:
+            print(f"No record found for emp id: {key}")
+
+        print(f"Current employee list: {self.dic}")
+
+# Example usage
+db = DB()
+
+# Add employees
+try:
+    db.set(101, ["Jassi", "ProdSec"])
+    db.set(102, ["Deep", "DevSecOps"])
+    db.set(103, ["Deepraj Barman", "Developer"])
+    db.set(104, ["Himanshu", "AppSec"])
+    # Attempting to add an employee with an existing key
+    db.set(101, ["Alex", "Security"])
+except (TypeError, ValueError) as e:
+    print(e)
+
+# Get emp details
+try:
+    details = db.get(102)
+    if details:
+        print(f"Emp id 102 details: {details}")
+except TypeError as e:
+    print(e)
+
+# Delete emp details
+try:
+    db.delete(102)
+except TypeError as e:
+    print(e)
+
+

exercises/in_memory_db_cmd.py

@@ -0,0 +1,109 @@
+# The problem requires implementing an in-memory key-value store
+# where you can set a key-value pair and
+# retrieve the value of a key.
+
+# Example:
+# db.set(101, ["Sanjeev", "ProdSec"])
+# db.set(102, ["Deep", "DevSecOps"])
+# db.get(102)
+# Think of command line for n inputs, set for n inputs, then based on command implement get, delete
+# Example:
+# Choose below options for operations:
+#     1. set/create entries
+#     How many entries: 2
+#     emp_id: input
+#     emp_details: input([])
+#     2. get emp_id details
+#     3. delete emp_id details
+#     4. update emp_id details
+
+import argparse
+
+class DB:
+
+    def __init__(self):
+        self.dic = {}
+
+    def set(self, key: int, value: list) -> None:
+        if not isinstance(key, int):
+            raise TypeError("Key must be an integer")
+        if not isinstance(value, list):
+            raise TypeError("Value must be a list")
+        if key in self.dic:
+            raise ValueError(f"Key {key} already exists")
+        self.dic[key] = value
+
+    def get(self, key: int) -> list:
+        if not isinstance(key, int):
+            raise TypeError("Key must be an integer")
+        if key in self.dic:
+            return self.dic[key]
+        else:
+            print(f"No record found for emp id: {key}")
+            return None
+
+    def delete(self, key: int) -> None:
+        if not isinstance(key, int):
+            raise TypeError("Key must be an integer")
+        if key in self.dic:
+            print(f"Deleting emp id {key} details: {self.dic[key]}")
+            del self.dic[key]
+            print(f"Emp id {key} deleted successfully.")
+        else:
+            print(f"No record found for emp id: {key}")
+
+        print(f"Current employee list: {self.dic}")
+
+def main():
+    parser = argparse.ArgumentParser(description="Database operations")
+    subparsers = parser.add_subparsers(dest="command")
+
+    # Set command
+    set_parser = subparsers.add_parser('set', help="Set a new entry")
+    set_parser.add_argument("key", type=int, help="Key (employee ID)")
+    set_parser.add_argument("value", type=str, nargs='+', help="Value (employee details)")
+
+    # Get command
+    get_parser = subparsers.add_parser("get", help="Get an entry")
+    get_parser.add_argument("key", type=int, help="Key (employee ID)")
+
+    # Delete command
+    delete_parser = subparsers.add_parser("delete", help="Delete an entry")
+    delete_parser.add_argument("key", type=int, help="Key (employee ID)")
+
+    args = parser.parse_args()
+    db = DB()
+
+    # Example preloaded entries
+    try:
+        db.set(101, ["Jassi", "ProdSec"])
+        db.set(102, ["Deep", "DevSecOps"])
+        db.set(103, ["Deepraj Barman", "Developer"])
+        db.set(104, ["Himanshu", "AppSec"])
+    except (TypeError, ValueError) as e:
+        print(e)
+
+    if args.command == "set":
+        try:
+            db.set(args.key, args.value)
+            print(f"Set key {args.key} with value {args.value}")
+        except (TypeError, ValueError) as e:
+            print(e)
+
+    elif args.command == "get":
+        try:
+            details = db.get(args.key)
+            if details:
+                print(f"Emp id {args.key} details: {details}")
+        except TypeError as e:
+            print(e)
+
+    elif args.command == "delete":
+        try:
+            db.delete(args.key)
+        except TypeError as e:
+            print(e)
+
+if __name__ == "__main__":
+    main()
+

exercises/in_memory_db_json.py

@@ -0,0 +1,158 @@
+# The problem requires implementing an in-memory key-value store
+# where you can set a key-value pair and
+# retrieve the value of a key.
+
+# Example:
+# db.set(101, ["Sanjeev", "ProdSec"])
+# db.set(102, ["Deep", "DevSecOps"])
+# db.get(102)
+# Think of command line for n inputs, set for n inputs, then based on command implement get, delete
+# Example:
+# Choose below options for operations:
+#     1. set/create entries
+#     How many entries: 2
+#     emp_id: input
+#     emp_details: input([])
+#     2. get emp_id details
+#     3. delete emp_id details
+#     4. update emp_id details
+# use loop for interactive session
+# usr argparse for cmd options
+# use json to store the data for permanent use
+# handle as much error as you can, also some edge cases
+import argparse
+import json
+import os
+
+class DB:
+    def __init__(self, filename='db.json'):
+        self.filename = filename
+        self.dic = self.load()
+
+    def load(self):
+        if os.path.exists(self.filename):
+            with open(self.filename, 'r') as f:
+                return json.load(f)
+        return {}
+
+    def save(self):
+        with open(self.filename, 'w') as f:
+            json.dump(self.dic, f, indent=4)
+
+    def set(self, key: int, value: list) -> None:
+        if not isinstance(key, int):
+            raise TypeError("Key must be an integer")
+        if not isinstance(value, list):
+            raise TypeError("Value must be a list")
+        if key in self.dic:
+            raise ValueError(f"Key {key} already exists")
+        self.dic[key] = value
+        self.save()
+
+    def get(self, key: int) -> list:
+        if not isinstance(key, int):
+            raise TypeError("Key must be an integer")
+        if key in self.dic:
+            return self.dic[key]
+        else:
+            print(f"No record found for emp id: {key}")
+            return None
+
+    def delete(self, key: int) -> None:
+        if not isinstance(key, int):
+            raise TypeError("Key must be an integer")
+        if key in self.dic:
+            print(f"Deleting emp id {key} details: {self.dic[key]}")
+            del self.dic[key]
+            print(f"Emp id {key} deleted successfully.")
+            self.save()
+        else:
+            print(f"No record found for emp id: {key}")
+        print(f"Current employee list: {self.dic}")
+
+def main():
+    db = DB()
+
+    parser = argparse.ArgumentParser(description="Database operations")
+    subparsers = parser.add_subparsers(dest="command")
+
+    # Set command
+    set_parser = subparsers.add_parser("set", help="Set a new entry")
+    set_parser.add_argument("key", type=int, help="Key (employee ID)")
+    set_parser.add_argument("value", nargs='+', help="Value (employee details)")
+
+    # Get command
+    get_parser = subparsers.add_parser("get", help="Get an entry")
+    get_parser.add_argument("key", type=int, help="Key (employee ID)")
+
+    # Delete command
+    delete_parser = subparsers.add_parser("delete", help="Delete an entry")
+    delete_parser.add_argument("key", type=int, help="Key (employee ID)")
+
+    args = parser.parse_args()
+
+    if args.command == "set":
+        try:
+            db.set(args.key, args.value)
+            print(f"Set key {args.key} with value {args.value}")
+        except (TypeError, ValueError) as e:
+            print(e)
+
+    elif args.command == "get":
+        try:
+            details = db.get(args.key)
+            if details:
+                print(f"Emp id {args.key} details: {details}")
+        except TypeError as e:
+            print(e)
+
+    elif args.command == "delete":
+        try:
+            db.delete(args.key)
+        except TypeError as e:
+            print(e)
+
+    else:
+        while True:
+            print("\nChoose an operation:")
+            print("1. Set a new entry")
+            print("2. Get an entry")
+            print("3. Delete an entry")
+            print("4. Exit")
+
+            choice = input("Enter your choice (1/2/3/4): ")
+
+            if choice == '1':
+                try:
+                    key = int(input("Enter key (employee ID): "))
+                    value = input("Enter value (employee details separated by spaces): ").split()
+                    db.set(key, value)
+                    print(f"Set key {key} with value {value}")
+                except (TypeError, ValueError) as e:
+                    print(e)
+
+            elif choice == '2':
+                try:
+                    key = int(input("Enter key (employee ID): "))
+                    details = db.get(key)
+                    if details:
+                        print(f"Emp id {key} details: {details}")
+                except TypeError as e:
+                    print(e)
+
+            elif choice == '3':
+                try:
+                    key = int(input("Enter key (employee ID): "))
+                    db.delete(key)
+                except TypeError as e:
+                    print(e)
+
+            elif choice == '4':
+                print("Exiting the program.")
+                break
+
+            else:
+                print("Invalid choice. Please choose a valid option.")
+
+if __name__ == "__main__":
+    main()