Unexpected column title causes problems in filters

[rpgoldman]

I have a pandas data table that is full of flow cytometry data -- this is data from a piece of cell biology measurement equipment. It has columns with different optical channels for each unit. The optical channels' names are all of this pattern 'XXX-Y', for example 'BL1-A'.
This causes problems with the query processing, because of two things:

1. the query interpreter misinterprets BL1-A as BL1 minus A
2. there is no feedback to the user to indicate a problem. I see the following in the shell (I started running DataExplore as python3 -m pandastable/main.py):

pandas.core.computation.ops.UndefinedVariableError: name 'BL1' is not defined

but if you are not looking at a terminal window, you won't see this.

I can enter this using the widgets, so I guess that's the work-around. But it would be nice to see the errors in interpreting the string. If I can figure it out, I'll try to make a PR for this.

[dmnfarrell]

Yes I just ignore the errors and throw them away which obviously is not that helpful. It would just mean printing the errors in the terminal. I don't think columns with such symbols can be interpreted. You could convert your column names using the tool in dataexplore to replace the -.

[rpgoldman]

Would it be possible to throw the errors into a pop-up menu? I've never used tkinter, but I have used Tcl+Tk, so if you could point me at code that pops up a modal dialog box, I will submit a merge request that makes these errors visible to the programmer.

[dmnfarrell]

Well for non programmers it could be annoying if a popup appears with every error. I was thinking it might be better to send the stack traces to a log using the logging module: https://realpython.com/python-logging/
Do you have an experience with that?

[rpgoldman]

No, I'm afraid I have never tried.
Note, though, that the string command, which is where this error arises, is not likely to be used by any but programmers, so a pop up might not be so bad.
A logger makes sense, though. I just haven't used one.
By the way, I have a tweaked version where I inserted an optional debugger from StackExchange that lets me throw into the debugger when I want to. I'll see about sharing that, if you are interested.

[dmnfarrell]

Sure you can show me how you do that. It could be best to create a debug mode that you activate and then it creates the popups but it might be a bit too ad hoc. I would prefer something simple to implement. I will look into the logging. It's something I would have done long ago if I had time.

[rpgoldman]

See #110. Note that this is not ready for merge -- it's just a starting point. But it might be helpful for you, as well as me.