This is quite an essential part of my program and I need to have sorted out as soon as possible so anything would be a massive help.
My program consists of three modules which are imported to each other. One module consists of my user interface for which I am using tkinter. The user inputs data on a canvas which is sent to a second program to be processed and is then sent to the third module which contains the algorithm which I intend to step through with the user.
The "first" and "third" modules can interact with each other and during certain points in explaining the algorithm I change the appearance of the canvas and some text on the interface. The third module should then pause (for which I'm currently using a basic sleep method), and wait (ideally it will wait for the user to press the "Next Step" button on the user interface). It is during this step that my interface decides that it wants to freeze.
Is there any way I can stop this?
Many thanks in advance.
Edit: I've found a way to fix this. Thank you for all the suggestions!
A GUI program is always waiting for some action to occur.  When actions do occur, the event code corresponding to that action is executed.  Therefore, there is no need to call sleep().   All you need to do is set it up so that the third program is executed from the appropriate event.
stop tkinter window from freezing while program is sleeping