def as_marc(self):
"""Returns the record serialized as MARC21."""
fields = b""
directory = b""
offset = 0
# build the directory
# each element of the directory includes the tag, the byte length of
# the field and the offset from the base address where the field data
# can be found
if self.leader[9] == "a" or self.force_utf8:
encoding = "utf-8"
else:
encoding = "iso8859-1"
for field in self.fields:
field_data = field.as_marc(encoding=encoding)
fields += field_data
if field.tag.isdigit():
directory += ("%03d" % int(field.tag)).encode(encoding)
else:
directory += ("%03s" % field.tag).encode(encoding)
directory += ("%04d%05d" %
(len(field_data), offset)).encode(encoding)
offset += len(field_data)
# directory ends with an end of field
directory += END_OF_FIELD.encode(encoding)
# field data ends with an end of record
fields += END_OF_RECORD.encode(encoding)
# the base address where the directory ends and the field data begins
base_address = LEADER_LEN + len(directory)
# figure out the length of the record
record_length = base_address + len(fields)
# update the leader with the current record length and base address
# the lengths are fixed width and zero padded
strleader = "%05d%s%05d%s" % (
record_length,
self.leader[5:12],
base_address,
self.leader[17:],
)
leader = strleader.encode(encoding)
return leader + directory + fields
def as_marc(self):
"""
returns the record serialized as MARC21
"""
fields = b''
directory = b''
offset = 0
# build the directory
# each element of the directory includes the tag, the byte length of
# the field and the offset from the base address where the field data
# can be found
if self.leader[9] == 'a' or self.force_utf8:
encoding = 'utf-8'
else:
encoding = 'iso8859-1'
for field in self.fields:
field_data = field.as_marc(encoding=encoding)
fields += field_data
if field.tag.isdigit():
directory += ('%03d' % int(field.tag)).encode(encoding)
else:
directory += ('%03s' % field.tag).encode(encoding)
directory += ('%04d%05d' % (len(field_data), offset)).encode(encoding)
offset += len(field_data)
# directory ends with an end of field
directory += END_OF_FIELD.encode(encoding)
# field data ends with an end of record
fields += END_OF_RECORD.encode(encoding)
# the base address where the directory ends and the field data begins
base_address = LEADER_LEN + len(directory)
# figure out the length of the record
record_length = base_address + len(fields)
# update the leader with the current record length and base address
# the lengths are fixed width and zero padded
strleader = '%05d%s%05d%s' % \
(record_length, self.leader[5:12], base_address, self.leader[17:])
self.leader = strleader.encode(encoding)
return self.leader + directory + fields
