I can use tensorflow、jupyter、matplotlib in nvidia:tensorflow container, but the pip list shows none of them

I can use tensorflow、jupyter、matplotlib in nvidia:tensorflow container, but the pip list shows none of them
I tried to pip install them, it did install without warning that it’s already exist.

How are the packages managed in the docker? is this a problem?

and one more question, there are python2 and python3 in the tf docker, I open jupyter with python3 defaultly, but when I open the terminal and do pip staff, it’s python2, is this a problem?

I am here to describe my question more clearly.
In jupyter with command !pip list
I saw no matplotlib or tensorflow in tensorflow container.
when I install matplotlib in terminal from “jupyter–new–terminal”, the matplotlib cannot be used in jupyter any more.
and I found that the tensorflow could not be imported too with error
“ImportError: No module named tensorflow”

there must be something that I misunderstand with packages in docker.
could you share some idea?

after I install jupyter in the instructions of object_detection_api,
when I restart the docker and jupyter, jupyter could not be started now, it says::::::::

[C 09:32:53.261 NotebookApp] Bad config encountered during initialization:
[C 09:32:53.261 NotebookApp] The ‘contents_manager_class’ trait of <notebook.notebookapp.NotebookApp object at 0x7f76283fdc90> instance must be a type, but ‘jupytext.TextFileContentsManager’ could not be imported