Summary:
- Removed string parsing and some type guessing code from parse_data.py. That logic is now implicitly done by ValueGuesser by leaving the initial column type as Any. parse_data.py mostly comes into play when importing files (e.g. Excel) containing values that already have types, i.e. numbers and dates.
- 0s and 1s are treated as numbers instead of booleans to keep imports lossless.
- Removed dateguess.py and test_dateguess.py.
- Changed what `guessDateFormat` does when multiple date formats work equally well for the given data, in order to be consistent with the old dateguess.py.
- Columns containing numbers are now always imported as Numeric, never Int.
- Removed `NullIfEmptyParser` because it was interfering with the new system. Its purpose was to avoid pointlessly changing a column from Any to Text when no actual data was inserted. A different solution to that problem was already added to `_ensure_column_accepts_data` in the data engine in a recent related diff.
Test Plan:
- Added 2 `nbrowser/Importer2` tests.
- Updated various existing tests.
- Extended testing of `guessDateFormat`. Added `guessDateFormats` to show how ambiguous dates are handled internally.
Reviewers: georgegevoian
Reviewed By: georgegevoian
Differential Revision: https://phab.getgrist.com/D3302
321019217d