TypeError: 'NoneType' object does not support item assignment?

Question

So I start a root screen with a \"file select\" and a \"go\" button. The go button is disabled and I want to make it active after the file has been selected. When I select

Answer 1

This line:

go=Tkinter.Button(text='file location',command=chooseDir,state=Tkinter.DISABLED).pack()

is creating a temporary object, then calling pack() on it. The pack method returns None, so go is assigned None.

Remove the .pack() then go will be the Button object. Then call go.pack().