Writing a whole record

from datarecord import write_record

write_record(revision.id, source, con)  # as a revision's layer
write_record(None, source, con, uri="out/")  # as a standalone directory

source is anything satisfying Record — including a framework object presenting itself as one, which is what puts read and write on a single seam. An existing layer directory is an error rather than an overwrite: frames are staged into a sibling path and renamed on success, so a source that fails validation leaves no layer rather than half of one (design).

Every column the schema declares a type for is cast to it on the way out, so a record's files carry the schema's types and a reader can trust them. Validation is structural — a long frame carries the format's columns, and an entity frame carries every dim it is keyed by.