Deactivating Python Virtual Environment Guide | Generated by AI

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Question: How do I deactivate a Python virtual environment and return to the default system Python?

Answer:

To exit/deactivate the virtual environment, simply run:

deactivate

After running deactivate, your prompt will change from (venv) lzw@to:... back to lzw@to:..., and you’ll be using the system Python again.


Verify you’re back to system Python:

which python3
python3 --version

In your case, since the venv was built with Python 3.13 (which isn’t installed), after deactivating you can run your command using the available system Python explicitly:

PYTORCH_ALLOC_CONF=expandable_segments:True \
python3.11 -u train.py config/train_fineweb_gpt3.py 2>&1 \
  | tee -a out-fineweb-gpt3/train.log

Or just python3 if it points to 3.11 or 3.12 on your system.


Optional — Recreate the venv with the correct Python version:

If you want to fix the venv properly instead of using system Python directly:

deactivate
rm -rf venv
python3.11 -m venv venv
source venv/bin/activate
pip install -r requirements.txt  # reinstall dependencies

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