lmdb
Universal Python binding for the LMDB 'Lightning' Database
Decision gist · record as of 2026-08-14
Yes, if you need a fast, embedded key-value database with transaction support and have Python >= 3.9. The package is actively maintained, has no known vulnerabilities, and offers pre-built wheels for most platforms. Verify that the OLDAP-2.8 license is compatible with your use case before committing to production use.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python >= 3.9; compiled C extension requires a C compiler or pre-built wheel for your platform.
- Medium install friction due to compiled C extension wheels, but pre-built wheels are available for common platforms (macOS, Linux, Windows) and Python versions 3.10–3.13.
- Last release 33 days ago; repository is active with 747 stars.
License · maintenance · safety
OLDAP-2.8 (unclear) — License treatment is unclear (OLDAP-2.8); review the repository's license file and terms before use in proprietary or redistributed software to confirm compatibility with your project.
last release 2026-07-12 (33 days) · last repo commit 2026-07-12 · 747 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 4,848,906 downloads/mo, #2,216 on PyPI
Alternatives
Verify before relying
import lmdb
env = lmdb.open('/path/to/db')
with env.begin(write=True) as txn:
txn.put(b'key', b'value')
with env.begin() as txn:
print(txn.get(b'key'))- Specific performance characteristics (throughput, latency, memory overhead) compared to other embedded databases.
- Whether OLDAP-2.8 license is compatible with your intended use case (proprietary, commercial, or open-source redistribution).
- Concurrency model and transaction isolation guarantees under multi-process or multi-threaded access patterns.
What it is and what it does
py-lmdb is a Python wrapper around the LMDB C library, a high-performance embedded key-value database that uses memory-mapped files for fast, efficient access. It allows you to store and retrieve binary data with ACID transaction support, making it suitable for applications that need a lightweight, durable local database without the overhead of a server process.
The package has been maintained since 2013 and currently supports Python 3.9 and later, including PyPy. It provides no runtime dependencies beyond the compiled LMDB library itself, so installation is straightforward on platforms with pre-built wheels. The library is commonly used in data-intensive applications, caching layers, and scenarios where you need fast, transactional access to structured data without running a separate database service.
Use it for
- Building a local cache layer for machine learning pipelines or data processing workflows that need fast key-value lookups.
- Storing embeddings or feature vectors in a searchable, persistent format for similarity search or retrieval tasks.
- Implementing a lightweight session store or state management system for applications that don't require a full database server.
- Archiving or indexing large datasets where memory-mapped access provides performance benefits over traditional file I/O.
- Creating a transaction-safe local database for desktop or embedded applications with minimal external dependencies.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you need a fast, embedded key-value database with transaction support and have Python >= 3.9.
The package is actively maintained, has no known vulnerabilities, and offers pre-built wheels for most platforms. Verify that the OLDAP-2.8 license is compatible with your use case before committing to production use.
Install
lmdb on PyPI
Before you install
Medium install friction due to compiled C extension wheels, but pre-built wheels are available for common platforms (macOS, Linux, Windows) and Python versions 3.10–3.13. Last release 33 days ago; repository is active with 747 stars.
Requires Python >= 3.9; compiled C extension requires a C compiler or pre-built wheel for your platform.
License in practice
License treatment is unclear (OLDAP-2.8); review the repository's license file and terms before use in proprietary or redistributed software to confirm compatibility with your project.
Quickstart
import lmdb
env = lmdb.open('/path/to/db')
with env.begin(write=True) as txn:
txn.put(b'key', b'value')
with env.begin() as txn:
print(txn.get(b'key'))Verify before relying
- Specific performance characteristics (throughput, latency, memory overhead) compared to other embedded databases.
- Whether OLDAP-2.8 license is compatible with your intended use case (proprietary, commercial, or open-source redistribution).
- Concurrency model and transaction isolation guarantees under multi-process or multi-threaded access patterns.
Package facts
| License | OLDAP-2.8 unclear |
| Python support | Supports the current Python release >=3.9 |
| Install friction | Medium. Platform-specific wheel |
| Runtime dependencies | None |
| Maintenance | Actively maintained 33 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 4,848,906 / month, #2,216 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Programming Language :: PythonProgramming Language :: Python :: 3Programming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Programming Language :: Python :: 3.9Programming Language :: Python :: Implementation :: CPythonProgramming Language :: Python :: Implementation :: PyPyTopic :: DatabaseTopic :: Database :: Database Engines/Servers |
Evidence: lmdb-2.3.0-cp310-cp310-macosx_10_9_x86_64.whl; lmdb-2.3.0-cp310-cp310-macosx_11_0_arm64.whl; lmdb-2.3.0-cp310-cp310-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl; lmdb-2.3.0-cp310-cp310-manylinux2014_x86_64.manylinux_2_17_x86_64.manylinux_2_28_x86_64.whl; lmdb-2.3.0-cp310-cp310-win_amd64.whl; lmdb-2.3.0-cp310-cp310-win_arm64.whl; lmdb-2.3.0-cp311-cp311-macosx_10_9_x86_64.whl; lmdb-2.3.0-cp311-cp311-macosx_11_0_arm64.whl; lmdb-2.3.0-cp311-cp311-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl; lmdb-2.3.0-cp311-cp311-manylinux2014_x86_64.manylinux_2_17_x86_64.manylinux_2_28_x86_64.whl; lmdb-2.3.0-cp311-cp311-win_amd64.whl; lmdb-2.3.0-cp311-cp311-win_arm64.whl; lmdb-2.3.0-cp312-cp312-macosx_10_13_x86_64.whl; lmdb-2.3.0-cp312-cp312-macosx_11_0_arm64.whl; lmdb-2.3.0-cp312-cp312-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl; lmdb-2.3.0-cp312-cp312-manylinux2014_x86_64.manylinux_2_17_x86_64.manylinux_2_28_x86_64.whl; lmdb-2.3.0-cp312-cp312-win_amd64.whl; lmdb-2.3.0-cp312-cp312-win_arm64.whl; lmdb-2.3.0-cp313-cp313-macosx_10_13_x86_64.whl; lmdb-2.3.0-cp313-cp313-macosx_11_0_arm64.whl
Tags
Let your AI agent find packages like this
Example. Real query, live index.
You found this page by searching. An agent finds it by wishing: SkillFed indexes 14,416 PyPI packages by what they can do, searchable in plain language.
wish › “lmdb python binding”
- lmdbProvides a Python binding to LMDB (Lightning Memory-Mapped Database),…
- ase-db-backendsProvides database backend implementations for ASE, supporting…
- arcticdbArcticDB is a serverless DataFrame database that stores and retrieves…
Give your agent the search over MCP, or paste the wish link into any chat.
More Database packages
psycopg2-binary is a PostgreSQL database adapter for Python that implements the DB API 2.0 specification, enabling Python applications to connect to and query PostgreSQL databases with thread-safe concurrent operations.
Python client library for connecting to and executing commands against Redis key-value stores, supporting both synchronous and asynchronous operations.
Install it if your application needs to interact with Redis; the only prerequisite is a running Redis server instance.
YDB Python SDK is the official client library for connecting to and querying YDB databases from Python applications.
Install it if you need to connect Python applications to YDB databases.
Connects Python applications to Snowflake data warehouses using the DB API 2.0 specification, enabling SQL queries, data transfers, and warehouse operations.
sqlparse tokenizes SQL text into a tree of statements, clauses, and expressions, and provides functions to split scripts, format queries, and inspect parsed tokens without validating dialect or syntax.
Install it if you need to manipulate, format, or analyze SQL text programmatically.
Provides base adapter protocols and shared functionality that database adapters use to integrate with dbt-core, handling connections, dialect translation, relation caching, and core interface management.
See also amulet-leveldb · tinydb · ZODB · plyvel · ase-db-backends · rocksdict · speedict · historydict · libsql-experimental · pymonetdb