# dataframe_for_reps_impl

Dataframe that constructs representations from the columns (and conversions between them) when a dataframe is loaded. A keyed_representation and a string_representation are constructed for each column, unless the column is made up only of numerical values, in which case a vector_representation is constructed.

# column_rep

    some_df column_rep column_name

Return a representation of the default type for the column `column_name`, if such exists. This is either the keyedrepresentation or the vectorrepresentation.

    some_df column_rep column_name rep_type

Return a representation of subtype `rep_type` for the column `column_name`, if such exists.

# conversion

    some_df conversion src_column tgt_column

Returns a dfrlookupconversion from the keyedrepresentation `src_column` of `some_df` to the default representation of `tgt_column` of `some_df`. A numerical column may not be the source.