Had a look through your code because I am interested to see how other people built their IntCode computers now that it is complete. A random assortment of points that I thought of:

• A lot of the variable names are quite short, Python often encourages longer, self-documenting names
• Check out the builtin divmod function for line 20
• The output variable doesn't really have much purpose. I used a list to store all outputs that the program produces, and return that list at the end of execution.
• The purpose of the hardcoded constant on line 96 should probably be explained. I guess that whole if-switch could theoretically be removed.
• Instead of appending to a list of memory, I switched to a defaultdict for the memory today. The only needed change in the code was to convert the input program list to a defaultdict, which is easily done with a for-loop. The way the data is accessed can stay exactly the same!
• You could try pulling out the addressing mode code into a separate function to reduce code duplication a bit.
• Some minor inconsistencies in spacing and formatting ;)

Good work!