ImportError: No module named decorator

TL;DR: networkx requires the decorator package and it is not installed. Run pip install decorator and networkx imports fine.

The error

ImportError: No module named decorator

Fix it

1. Install decorator:

   pip install decorator

Expected: install completes.

1. Verify:

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

Expected: prints the version, no error.

When this applies

Use this when import networkx raises the decorator error, common after --no-deps installs.

When it does not apply

If decorator is installed but networkx still fails, check for a broken install with pip check. If the error names a different module, install that one instead.

Compatibility

All networkx 2.x versions; decorator has always been required.

Root cause

networkx uses the decorator package for its decorator-heavy API (notable edge-attribute decorators). The dependency is declared, but installs that skip dependencies leave it out.

Edge cases

Very old decorator versions can break new networkx; installing normally gets a compatible one. In conda envs, install decorator from the same channel as networkx.