ImportError: cannot import name 'joblib' from 'sklearn.externals'

TL;DR: scikit-learn 0.23 removed its vendored joblib. Change from sklearn.externals import joblib to plain import joblib (install it if missing).

The error

ImportError: cannot import name 'joblib' from 'sklearn.externals'

Fix it

1. Replace the import:

   import joblib

   Expected: no import error.

2. If joblib is not installed:

   pip install joblib

3. Verify:

   python -c "import joblib; print(joblib.__version__)"

   Expected: prints a version.

When this applies

Use this when old code or tutorials do from sklearn.externals import joblib on scikit-learn 0.23+.

When it does not apply

If the error names a different sklearn.externals member (like six), that vendored copy is gone too; find its standalone package. If sklearn itself will not import, reinstall it.

Compatibility

scikit-learn 0.23+. Plain import joblib works on every sklearn version.

Root cause

sklearn used to vendor joblib under sklearn.externals. In 0.23 the vendored copy was dropped and joblib became a proper declared dependency, so the old import path no longer exists.

Edge cases

Old pickles saved with sklearn.externals.joblib still load fine with standalone joblib. If a requirements file pins ancient sklearn, upgrading sklearn is better than working around the import.

GitHub issue mosh-hamedani/python-supplementary-materials#1 reports ImportError: cannot import name 'joblib' from 'sklearn.externals' with a modern scikit-learn. The verified fix: sklearn 0.23 removed the vendored sklearn.externals.joblib, so the import becomes plain import joblib (installing the standalone joblib package if needed), which works on all sklearn versions. Full thread: https://github.com/mosh-hamedani/python-supplementary-materials/issues/1