How to use an Emulator and a MttQ broker?

[Frankduc]

pi@raspberrypi:~ $ pip freeze | grep pymongo
pymongo==3.4.0

for the gpio i tried inside and outside tkinter. i get one error or another actualy the same:

If i want to clear the histo window or limit the number of output to 20 lines. There must be a command to do that?