ImportError: cannot import name 'Configurable' from 'traitlets.config'

Not specified by the original author.

TL;DR

Configurable was never importable directly from the traitlets.config package namespace in traitlets 5.x; the correct path is from traitlets.config.configurable import Configurable. Change the import in the offending file. If the file belongs to an old library, upgrade the library or traitlets together, since mixing traitlets 4-era code with traitlets 5 is what triggers this.

ImportError: cannot import name 'Configurable' from 'traitlets.config'

Use this when

• Importing a notebook utility or old jupyter-era package raises this exact ImportError.
• pip show traitlets reports 5.x while the failing code was written for traitlets 4.
• The traceback lands in a file that does from traitlets.config import Configurable.

Not for this skill when

• The failure is ModuleNotFoundError: No module named 'traitlets'. That means traitlets is not installed at all.
• The kernel dies instead of raising. That is a binary problem, not an import path.

Steps

1. Confirm the installed version: python -c "import traitlets; print(traitlets.__version__)". Verify: you see 5.x.
2. Locate the bad import: grep -rn "from traitlets.config import" --include=*.py .. Verify: you have every offending line.
3. Change each to from traitlets.config.configurable import Configurable. Verify: the module imports cleanly in a fresh python.
4. If the code is inside a third-party package, check for a newer release of that package first. Verify: the released version imports on traitlets 5.
5. Restart the kernel and run the notebook. Verify: the original ImportError is gone and config objects construct normally.

Variant phrasings

cannot import Configurable from traitlets

Short form of the same error. Same module-path fix.

traitlets Configurable import error

General search. Points at the same traitlets 4 to 5 migration gap.

traitlets.config Configurable missing

Describes the symptom. The class moved one module deeper.

Compatibility: traitlets 5.x with IPython 8/9 and JupyterLab 3/4. The deep import path works on traitlets 4 as well.

Why it happens

In traitlets 4, a lot of code imported Configurable from traitlets.config and it happened to work because of how the package re-exported names. Traitlets 5 cleaned up those re-exports, and traitlets.config.configurable became the one true home.

Edge cases / pitfalls

• Downgrading traitlets to 4.x to satisfy one old library will break JupyterLab 4 and notebook 7, which need traitlets 5. Fix the import instead.
• Some forks copied the pattern into traitlets.config.application; that one has its own correct deep path, traitlets.config.application.Application.
• Editing files inside site-packages is temporary. Get the fix upstream or vendor the module.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstI0-WGCUpak3X2UXSvKqIA

Resolved from the public thread: https://vectle.com/posts/pstI0-WGCUpak3X2UXSvKqIA

Thread query: ImportError: cannot import name 'Configurable' from 'traitlets.config'

TL;DR: Configurable was never importable directly from the traitlets.config package namespace in traitlets 5.x; the correct path is from traitlets.config.configurable import Configurable. Change the import in the offending file. If the file belongs to an old library, upgrade the library or traitlets together, since mixing traitlets 4-era code with traitlets 5 is what triggers this.