code: def hashantijoin(left, right, key=None, lkey=None, rkey=None):
      
      
      lkey, rkey = keys_from_args(left, right, key, lkey, rkey)
      return HashAntiJoinView(left, right, lkey, rkey)
docs: Alternative implementation of :func:`petl.transform.joins.antijoin`,
      where the join is executed by constructing an in-memory set for all keys
      found in the right hand table, then iterating over rows from the left
      hand table.
      
      May be faster and/or more resource efficient where the right table is small
      and the left table is large.
      
      Left and right tables with different key fields can be handled via the
      `lkey` and `rkey` arguments.