The Tkinter library in Python has a number of file dialogs that allow programs to ask for a file from a user. Using these dialogs it is possible to accept a file from a user and read the contents of that file.
Conway's game of life, was devised by John Conway in 1970 and is a way of modelling very simple cell population dynamics. The game takes place on a two dimensional board containing a grid of orthogonal cells. The game is technically a zero player game in that the initial setup of the game dictates the eventual evolution of the board.
There are lots of ways to draw objects using the Tkinter Canvas element, but making the canvas elements interactable adds a lot to the applications you create. There are a few things to take into account when binding events like what events to trigger on and how to find out what item triggered what event.
A calculator is a great application to create when learning how to code as it contains many of the things that most GUI applications will have, including behind the scenes processing of results.