pip install -e ".[dev]"
If 🤗 Transformers was already installed in the virtual environment, remove
   it with pip uninstall transformers before reinstalling it in editable
   mode with the -e flag.
Depending on your OS, and since the number of optional dependencies of Transformers is growing, you might get a
   failure with this command. If that's the case make sure to install the Deep Learning framework you are working with
   (PyTorch, TensorFlow and/or Flax) then do: