Improve error messages for when multiple files are not loaded

[venitahagerty]

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Describe the Enhancement

In order to speed up processing in Python, multiple files are processed together as a batch. Transformations - like calculating fcst_init - are done at once for all of the files of the batch. This makes it difficult to give a message for which file had the error. In addition, determining which file had the error may increase processing time. A solution needs to be found that will improve error messaging for users without increasing processing time too much.

Time Estimate

3 days of work.
Issues should represent approximately 1 to 3 days of work.

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Define Related Issue(s)

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• METplus, MET, METdb, METviewer, METexpress, METcalcpy, METplotpy

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[mollybsmith-noaa]

I'm closing this issue because I added a try/catch in the middle of the data read loop, so one bad file will no longer cause lots of good files not to be loaded. See #295