ML Metadata

1.17.1 verified Fri May 01 auth: no python

A library for maintaining and managing metadata for ML artifacts, executions, and contexts. Current version: 1.17.1. Supports Python 3.9-3.11. Release cadence: roughly quarterly.

pip install ml-metadata

Common errors

error ImportError: cannot import name 'metadata_store' from 'ml_metadata' ↓

cause Incorrect import path; top-level ml_metadata does not contain metadata_store directly.

fix

Use 'from ml_metadata.metadata_store import metadata_store'.

error AttributeError: module 'ml_metadata' has no attribute 'MetadataStore' ↓

cause MetadataStore is a protobuf message, not a class in the ml_metadata module.

fix

Import the protobuf module: 'from ml_metadata.proto import metadata_store_pb2' and use 'metadata_store_pb2.MetadataStore'.

error TypeError: Can't instantiate abstract class MetadataStore with abstract methods... ↓

cause Trying to instantiate metadata_store.MetadataStore with wrong connection config or missing SetInParent on fake database.

fix

Use 'connection_config.fake_database.SetInParent()' before creating the store.

Warnings

breaking Deprecated GetLineageGraph API removed in v1.15.0; use GetLineageSubgraph instead. ↓

fix Replace calls to GetLineageGraph with GetLineageSubgraph.

deprecated Windows OS support is deprecated as of v1.15.0. ↓

fix Use Linux or macOS; consider running in a container.

deprecated Python 3.8 support dropped in v1.15.0; Python 3.7 support dropped in v1.13.0. ↓

fix Use Python 3.9, 3.10, or 3.11.

gotcha Protobuf version constraints: v1.17.0+ requires protobuf>=4.25.2,<5 for Python 3.11; protobuf>4.21.6,<5 for 3.9/3.10. ↓

fix Ensure protobuf is installed with correct version constraints.

Imports

metadata_store
wrong
```
import ml_metadata
```
correct
```
from ml_metadata.metadata_store import metadata_store
```
Top-level import does not expose the store; must use submodule

MetadataStore

wrong

from ml_metadata import MetadataStore

correct

from ml_metadata.proto import metadata_store_pb2

MetadataStore is a protobuf message, not a direct class

Quickstart

Initialize a fake in-memory MLMD store to verify installation.

import ml_metadata as mlmd
from ml_metadata.metadata_store import metadata_store
from ml_metadata.proto import metadata_store_pb2

connection_config = metadata_store_pb2.ConnectionConfig()
connection_config.fake_database.SetInParent()
store = metadata_store.MetadataStore(connection_config)
print('ML Metadata store initialized successfully')