Virtual Environments (venv) - python
Install requirements for virtual environment without activating
After creating the virtual environment, you can use its own pip3 binary to install your requirements in its virtual environment
/path/to/venv/bin/pip3 install -r /path/to/requirements.txt
Use certain requirements without activating venv
Likewise to the above, you can reference the venv's python path and it will use that environment
/path/to/venv/bin/python3 file.py