- Nicely put together simple time series code with new concepts (objects, GUI)
- Good use of Git (could be somewhat more finegrained, should have more informative commit messages than "Just some problems with matplotlib backend")
- Difficult to understand overall structure and purpose of different functions -- docstrings missing
- In general, some documentation / extra info would be helpful: What do you want to achieve? Why the GUI? ...
- Avoid wildcard imports at all cost! Makes things very hard to read and debug if you are not familiar with the modules.
- Directory should be clean -- README.md did not contain any information, hpfilter.py seems to be old code.