`DatasetColumn` and `DatasetColumnPair` should have `__repr__()` methods defined

[boyleconnor]

Currently, if you try to print a DatasetColumnPair (say, for debugging purposes), it will just show an empty list. This causes all kind of issues with automatically raised exceptions, etc.

[zanvari]

Hi,

I'd like to investigate this issue. I'll check whether the problem still exists on the current main branch and, if so, look into adding appropriate __repr__() implementations for DatasetColumn and DatasetColumnPair and open a PR if appropriate.

[zanvari]

Hi,
I looked into this issue and opened PR #765 with a proposed fix that adds __repr__() implementations for DatasetColumn and DatasetColumnPair, along with tests.