feat: Add __str__() methods to EventDataFrame and GazeDataFrame

[josephine-funken]

Description

Added string representations to EventDataFrame and GazeDataFrame

Fixes issue # 448

Implemented changes

Insert a description of the changes implemented in the pull request.

• Add EventDataFrame.__str__() method which includes frame in output
• Add GazeDataFrame.__str__() method which includes experiment and frame in output
• Remove the use of frame from all tutorial notebooks

Type of change

• New feature (non-breaking change which adds functionality)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (38e93da) to head (befc4f6).

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #727   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           60        60           
  Lines         2813      2823   +10     
  Branches       714       715    +1     
=========================================
+ Hits          2813      2823   +10     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[dkrako]

I noticed that a lot of print()statements are being used. this is because the python interpreter uses the __repr__() method right?

can you additionally implement a __repr__() method for both classes and that just forward to the __str__() method?

like this:

def __repr__(self): -> str:
    return self.__str__()

then you should be able to remove all the print statements in the notebooks and examples

[dkrako]

Great! I just did some minor reformattings in the notebokos.
Now its's ready to merge, thanks a lot for your work!