it should be
You are using python 3,
filedialog
(what you import on line 1), not tkFileDialog
You are using python 3,
tkFileDialog
is/was python2
If you can't explain it to a six year old, you don't understand it yourself, Albert Einstein
How to Ask Questions The Smart Way: link and another link
Create MCV example
Debug small programs
How to Ask Questions The Smart Way: link and another link
Create MCV example
Debug small programs