Much better & faster than programatically open an Terminal window and copying/pasting commands.
#!/bin/bash
osascript -e 'tell application "Terminal" to do script "source /path/to/project/folder/venv/bin/activate && python3 /path/to/project/folder/test.py"'
or as part of a Python script:
import os
os.system('osascript -e \'tell application "Terminal" to do script "source /path/to/project/folder/venv/bin/activate && python3 /path/to/project/folder/test.py"\'')