Filters where the given column matches the given predicate.
Execute a side effect function for every row in the frame, returning the same Frame.
Execute a side effect function for every row in the frame, returning the same Frame.
the function to execute
this frame, to allow for builder style chaining
Returns a new Frame where only each "step" row is retained.
Returns a new Frame where only each "step" row is retained. Ie, if step is 2 then rows 1,3,5,7 will be retainined and if step was 10, then 1,11,21,31 etc.