## The problem
After `pip install google-cloud-documentai==0.3.0` (successful install), I get: `ImportError: cannot import name 'documentai_v1beta3' from 'google.cloud' (unknown location)`. This happens in multiple environments, including a GCP notebook instance. The package installs fine but will not import. What is wrong?
## The fix
The package is fine - the environment is the problem. If you selected a GCP notebook instance pre-loaded for Apache Beam, its Jupyter kernel runs a different Python (`/root/apache-beam-custom/bin/python`) than the one pip installed into (`/opt/conda/...`). So the import fails even though `pip install` succeeded. Verify with `import sys; print(sys.executable)` in the notebook and compare it to the pip path. Fix it by pointing the kernel at the right Python, or (quick hack) append the site-packages path in the notebook: `sys.path.append('/opt/conda/lib/python3.7/site-packages')`. The reporter confirmed this exact mismatch was the cause.