If you do a pip list with pip 9.0.1 or later, something will come out.
$ pip list DEPRECATION: The default format will switch to columns in the future. You can use --format=(legacy|columns) (or define a format=(legacy|columns) in your pip.conf under the [list] section) to disable this warning.
As written, you can create pip.conf and set it, but I don't know where to put it in the first place. I can find some by google, but unfortunately I can't find any information about the Windows environment. In conclusion, it is recognized that you create a folder named "pip" in% APPDATA% and place it with the name "pip.ini".