Set size of data type in bytes
H5T.set_size(type_id,type_size)
H5T.set_size(type_id,type_size) sets the
total size in bytes for the data type specified by type_id.
If a variable length string is desired then type_size can
be specified as 'H5T_VARIABLE'.
Create a variable length string with null termination.
type_id = H5T.copy('H5T_C_S1'); H5T.set_size(type_id,'H5T_VARIABLE'); H5T.set_strpad(type_id,'H5T_STR_NULLTERM');