Returns an iterator over the frame’s columns.

The iterator is a light-weight object of type frame_iterator, which yields consequent columns of the frame with each iteration.

Thus, the iterator produces the sequence frame[0], frame[1], frame[2], ... until the end of the frame. This works even if the user adds or deletes columns in the frame while iterating. Be careful when inserting/deleting columns at an index that was already iterated over, as it will cause some columns to be skipped or visited more than once.

This method is not intended for manual use. Instead, it is invoked by Python runtime either when you call iter(), or when you use the frame in a loop:

for column in frame: # column is a Frame of shape (frame.nrows, 1) ...