datatable.join()¶
Join clause for use in Frame’s square-bracket selector.
This clause is equivalent to the SQL JOIN
, though for the moment
datatable only supports left outer joins. In order to join,
the frame
must be keyed
first, and then joined
to another frame DT
as
DT[:, :, join(X)]
provided that DT
has the column(s) with the same name(s) as
the key in frame
.
Parameters¶
frame
Frame
An input keyed frame to be joined to the current one.
return
Join Object
In most of the cases the returned object is directly used in the Frame’s square-bracket selector.
except
TypeError
The exception is raised if the input frame is missing.
except
ValueError
The exception is raised if frame
is not keyed.