datatable.union()

Find the union of values in all frames.

Each frame should have only a single column or be empty. The values in each frame will be treated as a set, and this function will perform the union operation on these sets.

The dt.union(*frames) operation is equivalent to dt.unique(dt.rbind(*frames)).

Parameters

*frames
Frame | Frame | ...

Input single-column frames.

return
Frame

A single-column frame. The column stype is the smallest common stype of columns in the frames.

except
ValueError

The exception is raised when one of the input frames has more than one column.

except
NotImplementedError

The exception is raised when one of the frame columns has stype obj64.

See Also

  • intersect() – calculate the set intersection of values in the frames.

  • setdiff() – calculate the set difference between the frames.

  • symdiff() – calculate the symmetric difference between the sets of values in the frames.

  • unique() – find unique values in a frame.