The attribute’s memory datatype is specified with mem_type_id. The entire attribute is written to the file.

If mem_type_id is either a fixed-length or variable-length string, it is important to set the string length when defining the datatype. String datatypes are derived from 'H5T_C_S1' (or 'H5T_FORTRAN_S1' for Fortran), which defaults to 1 character in size. See H5T.set_size.

Datatype conversion takes place at the time of a read or write and is automatic.

See also: H5A.read

Source Code: H5A.write