{"library":"lmdb","title":"LMDB Python Binding","description":"lmdb (py-lmdb) is a universal Python binding for the LMDB 'Lightning' Database, a fast, memory-efficient, embedded key-value store. It provides an ordered map interface, multi-version concurrency control (MVCC) with reader/writer transactions, and utilizes memory-mapped files for zero-copy operations. The library is actively maintained, with frequent releases; the current version is 2.2.0.","language":"python","status":"active","last_verified":"Wed May 13","install":{"commands":["pip install lmdb"],"cli":null},"imports":["import lmdb"],"auth":{"required":false,"env_vars":[]},"quickstart":{"code":"import lmdb\nimport os\nimport shutil\n\ndb_path = './my_lmdb_data'\n\n# Ensure cleanup for demonstration\nif os.path.exists(db_path):\n    shutil.rmtree(db_path)\n\n# 1. Open an LMDB environment\n# map_size: Maximum size of the database. Crucial to set correctly.\n# max_dbs: Max number of named databases (sub-databases).\nenv = lmdb.open(db_path, map_size=10*1024*1024, max_dbs=10, subdir=True)\n\n# 2. Write data to the database\nwith env.begin(write=True) as txn:\n    txn.put(b'my_key_1', b'my_value_1')\n    txn.put(b'my_key_2', b'my_value_2')\n    txn.put(b'another_key', b'another_value')\n    print(\"Wrote data to LMDB.\")\n\n# 3. Read data from the database\nwith env.begin() as txn:\n    value1 = txn.get(b'my_key_1')\n    value_non_existent = txn.get(b'non_existent_key')\n    print(f\"Value for my_key_1: {value1.decode('utf-8') if value1 else None}\")\n    print(f\"Value for non_existent_key: {value_non_existent}\")\n\n    # Iterate through all key-value pairs\n    print(\"\\nAll items in DB:\")\n    for key, value in txn.cursor():\n        print(f\"  {key.decode('utf-8')}: {value.decode('utf-8')}\")\n\n# 4. Close the environment\nenv.close()\nprint(\"\\nLMDB environment closed.\")\n\n# Cleanup (optional, for examples)\nif os.path.exists(db_path):\n    shutil.rmtree(db_path)\n    print(f\"Cleaned up database at {db_path}\")","lang":"python","description":"This quickstart demonstrates how to open an LMDB environment, write key-value pairs, read specific values, iterate through all entries using a cursor, and properly close the environment. Note the use of byte strings for keys and values, and the importance of `map_size` and `max_dbs` configuration. The example also includes basic cleanup.","tag":null,"tag_description":null,"last_tested":"2026-04-25","results":[{"runtime":"python:3.10-alpine","exit_code":1},{"runtime":"python:3.10-slim","exit_code":0},{"runtime":"python:3.11-alpine","exit_code":1},{"runtime":"python:3.11-slim","exit_code":0},{"runtime":"python:3.12-alpine","exit_code":1},{"runtime":"python:3.12-slim","exit_code":0},{"runtime":"python:3.13-alpine","exit_code":1},{"runtime":"python:3.13-slim","exit_code":0},{"runtime":"python:3.9-alpine","exit_code":1},{"runtime":"python:3.9-slim","exit_code":0}]},"compatibility":{"tag":null,"tag_description":null,"last_tested":"2026-05-13","installed_version":"2.2.0","pypi_latest":"2.2.0","is_stale":false,"summary":{"python_range":"3.10–3.9","success_rate":50,"avg_install_s":1.6,"avg_import_s":0,"wheel_type":"wheel"},"results":[{"runtime":"python:3.10-alpine","python_version":"3.10","os_libc":"alpine 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