pip backup requirements lib in original env

 Standard Virtual Environment (venv or virtualenv)

The "original" and most common way to back up a virtual environment is not to copy the folder itself (which often breaks due to hardcoded paths), but to "freeze" its state into a list of dependencies. 

• Export (Backup): Run this command inside your activated environment.
  bash

  pip freeze > requirements.txt
  

  請謹慎使用程式碼。
  This creates a file named requirements.txt containing every package and its exact version.
• Restore: To recreate the environment elsewhere, create a new venv and run:
  bash

  pip install -r requirements.txt
  

  請謹慎使用程式碼。