Simple Key-Value Store with Shelve
This utility creates a persistent, dictionary-like key-value store using the shelve module. It allows you to store strings, numbers, and other Python objects to a local file and retrieve them later via the command line.
Modules Used:
The Code
Save this as kv_store.py.
import shelve
import argparse
import sys
DB_FILE = "my_store"
def add_item(key, value):
with shelve.open(DB_FILE, writeback=True) as db:
db[key] = value
print(f"Stored: '{key}' -> '{value}'")
def get_item(key):
with shelve.open(DB_FILE) as db:
if key in db:
print(f"{key}: {db[key]}")
else:
print(f"Error: Key '{key}' not found.")
def delete_item(key):
with shelve.open(DB_FILE) as db:
if key in db:
del db[key]
print(f"Deleted key: '{key}'")
else:
print(f"Error: Key '{key}' not found.")
def list_items():
with shelve.open(DB_FILE) as db:
if not db:
print("Store is empty.")
return
print(f"{'Key':<20} {'Value'}")
print("-" * 40)
for key, value in db.items():
print(f"{key:<20} {value}")
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Simple Key-Value Store using Shelve")
subparsers = parser.add_subparsers(dest="command", help="Command to run")
# Add Command
add_parser = subparsers.add_parser("add", help="Add a key-value pair")
add_parser.add_argument("key", help="The key")
add_parser.add_argument("value", help="The value")
# Get Command
get_parser = subparsers.add_parser("get", help="Retrieve a value by key")
get_parser.add_argument("key", help="The key to retrieve")
# Delete Command
del_parser = subparsers.add_parser("delete", help="Delete a key-value pair")
del_parser.add_argument("key", help="The key to delete")
# List Command
list_parser = subparsers.add_parser("list", help="List all keys and values")
args = parser.parse_args()
if args.command == "add":
add_item(args.key, args.value)
elif args.command == "get":
get_item(args.key)
elif args.command == "delete":
delete_item(args.key)
elif args.command == "list":
list_items()
else:
parser.print_help()Usage
# Add items
python kv_store.py add username "admin"
python kv_store.py add port 8080
# Retrieve an item
python kv_store.py get username
# List all items
python kv_store.py list
# Delete an item
python kv_store.py delete port