Selecting a file in a directory

[vsoler]

Hi,

My python script needs to work with a .txt file in a directory. I
would like to give the user the possibility to choose the file he
needs to work on in as much the same way as I open a .xls file in
Excel, that is, I want to make appear the "Windows'" window and let
the user choose.

I think this should be quite straightforward.

How should I proceed?