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 "k" row is retained.
Returns a new Frame where only each "k" row is retained. Ie, if sample is 2, then on average, every other row will be returned. If sample is 10 then only 10% of rows will be returned. When running concurrently, the rows that are sampled will vary depending on the ordering that the workers pull through the rows. Each iterator (thread) uses its own count for the sample.