What happens when importing lamindb and the instance is not yet setup?

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!lamin disconnect

• no instance loaded

# !pip install 'lamindb[jupyter]'
import lamindb as ln
import pytest

! To use lamindb, you need to connect to an instance.

Connect to an instance: `ln.connect()`. Init an instance: `ln.setup.init()`.

If you used the CLI to set up lamindb in a notebook, restart the Python session.

If you try to use lamindb, it will raise an InstanceNotSetupError and ask you to init or load an instance via the python API.

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with pytest.raises(ln._InstanceNotSetupError):
    ln.track()

ln.setup.init(storage="./testsetup")

→ initialized lamindb: testuser1/testsetup

Now we can access functionality:

ln.track("2lhqA4uTKSFP0000")

→ created Transform('2lhqA4uTKSFP0000'), started new Run('lHiAyTra...') at 2025-07-15 12:57:31 UTC

→ notebook imports: lamindb==1.8.0 pytest==8.4.1

Let us try to init another instance in the same Python session: It doesn’t work.

# from lamindb_setup._init_instance import CannotSwitchDefaultInstance

# with pytest.raises(CannotSwitchDefaultInstance):
#    ln.setup.init(storage="./testsetup2")

!lamin delete --force testsetup

• deleting instance testuser1/testsetup