datatable.Frame.rbind()

Append rows of frames to the current frame.

This is equivalent to list.extend() in Python: the frames are combined by rows, i.e. rbinding a frame of shape [n x k] to a Frame of shape [m x k] produces a frame of shape [(m + n) x k].

This method modifies the current frame in-place. If you do not want the current frame modified, then use the dt.rbind() function.

If frame(s) being appended have columns of types different from the current frame, then these columns will be promoted to the largest of their types: bool -> int -> float -> string.

If you need to append multiple frames, then it is more efficient to collect them into an array first and then do a single rbind(), than it is to append them one-by-one in a loop.

Appending data to a frame opened from disk will force loading the current frame into memory, which may fail with an OutOfMemory exception if the frame is sufficiently big.

Parameters

frames
Frame | List[Frame]

One or more frames to append. These frames should have the same columnar structure as the current frame (unless option force is used).

force
bool

If True, then the frames are allowed to have mismatching set of columns. Any gaps in the data will be filled with NAs.

bynames
bool

If True (default), the columns in frames are matched by their names. For example, if one frame has columns [“colA”, “colB”, “colC”] and the other [“colB”, “colA”, “colC”] then we will swap the order of the first two columns of the appended frame before performing the append. However if bynames is False, then the column names will be ignored, and the columns will be matched according to their order, i.e. i-th column in the current frame to the i-th column in each appended frame.

return
None