Memory usage increases until it fills my RAM and locks my PC/Laptop

Here is my screen record to show it:

https://www.youtube.com/watch?v=B3_0iTqkqkg

CPU architecture: 64 bit Intel
OS:Linux/Manjaro/KDE
Python version: 3.8.6
bpython version: 0.18, 0.19, 0.20 (didnt tested with older versions)

Same thing appears with my laptop too.