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DictDB

DictDB Logo

DictDB is an in-memory, dictionary-based database for Python with SQL-like CRUD operations, optional schemas, fast lookups via indexes, and a fluent query DSL.

Perfect for prototyping, testing, and lightweight relational workflows without a full database engine.

Features

  • SQL-like CRUD - insert, select, update, delete, upsert with familiar semantics
  • Fluent Query DSL - Build conditions with Python operators: table.age >= 18, table.name.like("A%")
  • Logical Operators - Readable And, Or, Not functions for complex queries
  • Aggregations - Count, Sum, Avg, Min, Max with GROUP BY support
  • Indexes - Hash indexes for O(1) equality lookups, sorted indexes for range queries
  • Optional Schemas - Type validation when you need it, flexibility when you don't
  • CSV Import/Export - Load data from CSV files and export query results
  • Persistence - Save/load to JSON or Pickle
  • Automatic Backups - Periodic and incremental backup support
  • Thread-Safe - Reader-writer locks for concurrent access
  • Async Support - Non-blocking save/load operations
  • Zero Config - No server, no setup, just Python

Quick Example

from dictdb import DictDB, And

# Create database and table
db = DictDB()
db.create_table("users", primary_key="id")
users = db.get_table("users")

# Insert records
users.insert({"name": "Alice", "age": 30, "role": "admin"})
users.insert({"name": "Bob", "age": 25, "role": "user"})

# Query with fluent DSL (Condition wrapper is optional)
admins = users.select(where=users.role == "admin")
adults = users.select(where=users.age >= 18)

# Combine conditions with And/Or/Not
senior_admins = users.select(where=And(users.role == "admin", users.age >= 30))

# Update and delete
users.update({"age": 31}, where=users.name == "Alice")
users.delete(where=users.name == "Bob")

# Persist to disk
db.save("data.json", file_format="json")

Installation

pip install dctdb

from dictdb import DictDB, Condition

Package name

The PyPI package is dctdb, but the import name is dictdb.

Requirements

  • Python 3.13+

License

Apache License 2.0 - see LICENSE for details.