Describe the bug
There are two bugs that were discovered with the DFEncoder classes:

1. When a column has all identical values, the standard deviation can be 0 causing a divide by 0 error in the scalar
2. When the column reconstruction chooses _other as the most likely value, an index out of range error can occur since the column categories dont include _other by default.

Both of these bugs have already been fixed internally. The fixes need to be applied and tested to the new repo.