如何查看 virtualenv 中 package 版本的历史记录？

Question

I want to know what was the previous version of package that was installed in my vitrualenv before I have upgraded it. Lets say I have lib==1.1.0 then I upgrade it using pip install upgrade lib==1.2.0 and after that I want to check what was the previous version ( 1.1.0 )

Answer 1

what was the previous version of package that was installed in my vitrualenv

Unfortunaltey, a virtualenv does not keep track of changes made to it.

As @Grismar pointed out, you may "freeze" the list of all installed packages, and then re-install to the previous set at a later point:

$ pip freeze > requirements.txt   
$ pip install -r requirements.txt