How would I
1. Access windows explorer
2. Use it to to gain the path to a file. For example when I click "open" it pastes the address of the selected file into an entry box
I'm using tkinter if that helps at all.
Thanks in advance.
Import tkinter.filedialog with a statement such as from tkinter import filedialog (3.x) or import FileDialog as filedialog (2.x).  This module is not properly documented in the CPython docs, nor anywhere else I know of, so read the code to determine which of the ask... methods you want to use.  In 3.x, the code is Lib/tkinter/filedialog.py.  In 2.x, Lib/libtk/FileDialog.py.
EDIT: From what you said, you may want either askopenfilename or askopenfilenames.  I believe these return names without opening the files.  The functions without name actually open the files.
Use Windows explorer to get the path to a file in python