def _save(self, file_to_write, overwrite):
if overwrite:
file_to_write = self.filename
elif os.path.isfile(file_to_write):
msg = 'File ' + file_to_write + ' already exists !\n' + \
'Call save() with "overwrite = True" to overwrite the file.'
raise IOError(msg)
encoder = pvl.encoder.PDSLabelEncoder
serial_label = pvl.dumps(self.label, cls=encoder)
label_sz = len(serial_label)
image_pointer = int(label_sz / self.label['RECORD_BYTES']) + 1
self.label['^IMAGE'] = image_pointer + 1
diff = 0
if len(pvl.dumps(self.label, cls=encoder)) != label_sz:
diff = label_sz - len(pvl.dumps(self.label, cls=encoder))
pvl.dump(self.label, file_to_write, cls=encoder)
offset = image_pointer * self.label['RECORD_BYTES'] - label_sz
stream = open(file_to_write, 'a')
for i in range(0, offset+diff):
stream.write(" ")
if (self._bands > 1 and self._format != 'BAND_SEQUENTIAL'):
raise NotImplementedError
else:
self.data.tofile(stream, format='%' + self._sample_type[1])
stream.close()
def pvl_flavor(
text, dialect, decenc: dict, filename, verbose=False
) -> tuple((bool, bool)):
"""Returns a two-tuple of booleans which indicate
whether the *text* could be loaded and then encoded.
The first boolean in the two-tuple indicates whether the *text*
could be loaded with the given parser, grammar, and decoder.
The second indicates whether the loaded PVL object could be
encoded with the given encoder, grammar, and decoder. If the
first element is False, the second will be None.
"""
loads = None
encodes = None
try:
some_pvl = pvl.loads(text, **decenc)
loads = True
try:
pvl.dumps(some_pvl, **decenc)
encodes = True
except (LexerError, ParseError, ValueError) as err:
logging.error(f"{dialect} encode error {filename} {err}")
encodes = False
except (LexerError, ParseError) as err:
logging.error(f"{dialect} load error {filename} {err}")
loads = False
return (loads, encodes)
def _save(self, file_to_write, overwrite):
"""Save PDS3Image object as PDS3 file.
Parameters
----------
Overwrite: Use this keyword to save image with same filename.
Examples
--------
>>> from planetaryimage import PDS3Image
>>> image = PDS3Image.open('tests/mission_data/2p129641989eth0361p2600r8m1.img')
>>> image.save('temp.IMG')
>>> image.save('temp.IMG', overwrite=True)
"""
if overwrite:
file_to_write = self.filename
elif os.path.isfile(file_to_write):
msg = 'File ' + file_to_write + ' already exists !\n' + \
'Call save() with "overwrite = True" to overwrite the file.'
raise IOError(msg)
encoder = pvl.encoder.PDSLabelEncoder
serial_label = pvl.dumps(self.label, cls=encoder)
label_sz = len(serial_label)
image_pointer = int(label_sz / self.label['RECORD_BYTES']) + 1
self.label['^IMAGE'] = image_pointer + 1
if self._sample_bytes != self.label['IMAGE']['SAMPLE_BITS'] * 8:
self.label['IMAGE']['SAMPLE_BITS'] = self.data.itemsize * 8
sample_type_to_save = self.DTYPES[self._sample_type[0] + self.dtype.kind]
self.label['IMAGE']['SAMPLE_TYPE'] = sample_type_to_save
if len(self.data.shape) == 3:
self.label['IMAGE']['BANDS'] = self.data.shape[0]
self.label['IMAGE']['LINES'] = self.data.shape[1]
self.label['IMAGE']['LINE_SAMPLES'] = self.data.shape[2]
else:
self.label['IMAGE']['BANDS'] = 1
self.label['IMAGE']['LINES'] = self.data.shape[0]
self.label['IMAGE']['LINE_SAMPLES'] = self.data.shape[1]
diff = 0
if len(pvl.dumps(self.label, cls=encoder)) != label_sz:
diff = abs(label_sz - len(pvl.dumps(self.label, cls=encoder)))
pvl.dump(self.label, file_to_write, cls=encoder)
offset = image_pointer * self.label['RECORD_BYTES'] - label_sz
stream = open(file_to_write, 'a')
for i in range(0, offset+diff):
stream.write(" ")
if (self._bands > 1 and self._format != 'BAND_SEQUENTIAL'):
raise NotImplementedError
else:
self.data.tofile(stream, format='%' + self.dtype.kind)
stream.close()
def _save(self, file_to_write, overwrite):
"""Save PDS3Image object as PDS3 file.
Parameters
----------
filename: Set filename for the pds image to be saved.
Overwrite: Use this keyword to save image with same filename.
Usage: image.save('temp.IMG', overwrite=True)
"""
if overwrite:
file_to_write = self.filename
elif os.path.isfile(file_to_write):
msg = 'File ' + file_to_write + ' already exists !\n' + \
'Call save() with "overwrite = True" to overwrite the file.'
raise IOError(msg)
encoder = pvl.encoder.PDSLabelEncoder
serial_label = pvl.dumps(self.label, cls=encoder)
label_sz = len(serial_label)
image_pointer = int(label_sz / self.label['RECORD_BYTES']) + 1
self.label['^IMAGE'] = image_pointer + 1
if self._sample_bytes != self.label['IMAGE']['SAMPLE_BITS'] * 8:
self.label['IMAGE']['SAMPLE_BITS'] = self.data.itemsize * 8
sample_type_to_save = self.DTYPES[self._sample_type[0] +
self.dtype.kind]
self.label['IMAGE']['SAMPLE_TYPE'] = sample_type_to_save
if len(self.data.shape) == 3:
self.label['IMAGE']['BANDS'] = self.data.shape[0]
self.label['IMAGE']['LINES'] = self.data.shape[1]
self.label['IMAGE']['LINE_SAMPLES'] = self.data.shape[2]
else:
self.label['IMAGE']['BANDS'] = 1
self.label['IMAGE']['LINES'] = self.data.shape[0]
self.label['IMAGE']['LINE_SAMPLES'] = self.data.shape[1]
diff = 0
if len(pvl.dumps(self.label, cls=encoder)) != label_sz:
diff = abs(label_sz - len(pvl.dumps(self.label, cls=encoder)))
pvl.dump(self.label, file_to_write, cls=encoder)
offset = image_pointer * self.label['RECORD_BYTES'] - label_sz
stream = open(file_to_write, 'a')
for i in range(0, offset + diff):
stream.write(" ")
if (self._bands > 1 and self._format != 'BAND_SEQUENTIAL'):
raise NotImplementedError
else:
self.data.tofile(stream, format='%' + self.dtype.kind)
stream.close()
def test_special_strings():
module = pvl.PVLModule([
('single_quote', "'"),
('double_quote', '"'),
('mixed_quotes', '"\''),
])
assert module == pvl.loads(pvl.dumps(module))
encoder = pvl.encoder.IsisCubeLabelEncoder
assert module == pvl.loads(pvl.dumps(module, cls=encoder))
encoder = pvl.encoder.PDSLabelEncoder
assert module == pvl.loads(pvl.dumps(module, cls=encoder))
def test_special_values():
module = pvl.PVLModule([
('bool_true', True),
('bool_false', False),
('null', None),
])
assert module == pvl.loads(pvl.dumps(module))
encoder = pvl.encoder.IsisCubeLabelEncoder
assert module == pvl.loads(pvl.dumps(module, cls=encoder))
encoder = pvl.encoder.PDSLabelEncoder
assert module == pvl.loads(pvl.dumps(module, cls=encoder))
def test_special_values():
module = pvl.PVLModule([
('bool_true', True),
('bool_false', False),
('null', None),
])
assert module == pvl.loads(pvl.dumps(module))
encoder = pvl.encoder.IsisCubeLabelEncoder
assert module == pvl.loads(pvl.dumps(module, cls=encoder))
encoder = pvl.encoder.PDSLabelEncoder
assert module == pvl.loads(pvl.dumps(module, cls=encoder))
def test_special_strings():
module = pvl.PVLModule([
('single_quote', "'"),
('double_quote', '"'),
('mixed_quotes', '"\''),
])
assert module == pvl.loads(pvl.dumps(module))
encoder = pvl.encoder.IsisCubeLabelEncoder
assert module == pvl.loads(pvl.dumps(module, cls=encoder))
encoder = pvl.encoder.PDSLabelEncoder
assert module == pvl.loads(pvl.dumps(module, cls=encoder))
def _save(self, file_to_write, overwrite):
"""
Redefine _save() used in PDS3Image() so it does not overwrite the comment
lines we add in with PDS3LabelEncoder()
"""
# if overwrite:
## file_to_write = self.filename
# elif os.path.isfile(file_to_write):
# msg = 'File ' + file_to_write + ' already exists !\n' + \
## 'Call save() with "overwrite = True" to overwrite the file.'
## raise IOError(msg)
# with open(file_to_write, 'a+b') as stream:
encoder = PDS3LabelEncoder
serial_label = pvl.dumps(self.label, cls=encoder)
label_sz = len(serial_label)
image_pointer = int(label_sz / self.label['RECORD_BYTES']) + 1
self.label['^IMAGE'] = image_pointer + 1
if self._sample_bytes != self.label['IMAGE']['SAMPLE_BITS'] * 8:
self.label['IMAGE']['SAMPLE_BITS'] = self.data.itemsize * 8
sample_type_to_save = self.DTYPES[self._sample_type[0] +
self.dtype.kind]
self.label['IMAGE']['SAMPLE_TYPE'] = sample_type_to_save
if len(self.data.shape) == 3:
self.label['IMAGE']['BANDS'] = self.data.shape[0]
self.label['IMAGE']['LINES'] = self.data.shape[1]
self.label['IMAGE']['LINE_SAMPLES'] = self.data.shape[2]
else:
self.label['IMAGE']['BANDS'] = 1
self.label['IMAGE']['LINES'] = self.data.shape[0]
self.label['IMAGE']['LINE_SAMPLES'] = self.data.shape[1]
diff = 0
if len(pvl.dumps(self.label, cls=encoder)) != label_sz:
diff = abs(label_sz - len(pvl.dumps(self.label, cls=encoder)))
pvl.dump(self.label, file_to_write, cls=encoder)
offset = image_pointer * self.label['RECORD_BYTES'] - label_sz
stream = open(file_to_write, 'a')
for i in range(0, offset + diff):
stream.write(" ")
if (self._bands > 1 and self._format != 'BAND_SEQUENTIAL'):
raise NotImplementedError
else:
self.data.tofile(stream, format='%' + self.dtype.kind)
stream.close()
def _update_label(self, label, array):
"""Update PDS3 label for NumPy Array.
It is called by '_create_label' to update label values
such as,
- ^IMAGE, RECORD_BYTES
- STANDARD_DEVIATION
- MAXIMUM, MINIMUM
- MEDIAN, MEAN
** Currently lines are commented out because these values are not desired by users.
Returns
-------
Update label module for the NumPy array.
Usage: self.label = self._update_label(label, array)
"""
maximum = float(np.max(array))
mean = float(np.mean(array))
median = float(np.median(array))
minimum = float(np.min(array))
stdev = float(np.std(array, ddof=1))
encoder = pvl.encoder.PDSLabelEncoder
serial_label = pvl.dumps(label, cls=encoder)
label_sz = len(serial_label)
image_pointer = int(label_sz / label['RECORD_BYTES']) + 1
label['^IMAGE'] = image_pointer + 1
label['LABEL_RECORDS'] = image_pointer
return label
def Map2pvl(self):
self.mapDICT['End_Group'] = 'Mapping'
mappvl = pvl.dumps(self.mapDICT)
self.mappvl = mappvl
return mappvl
def Map2File(self, filename):
self.mapDICT['End_Group'] = 'Mapping'
tempPVL = pvl.dumps(self.mapDICT)
file = open(filename, 'w')
file.write(tempPVL)
file.close()
def test_special_strings():
module = pvl.PVLModule([
("single_quote", "'"),
("double_quote", '"'),
# ('mixed_quotes', '"\''), # see above about escaped quotes.
])
assert module == pvl.loads(
pvl.dumps(module, encoder=pvl.encoder.PVLEncoder()))
def create_pvl_header(self, version, headerstartbyte, networkid,
targetname, description, username,
buffer_header_size, points_bytes, creation_date,
modified_date):
"""
Create the PVL header object
Parameters
----------
version : int
The current ISIS version to write, defaults to 2
headerstartbyte : int
The seek offset that the protocol buffer header starts at
networkid : str
The name of the network
targetname : str
The name of the target, e.g. Moon
description : str
A description for the network.
username : str
The name of the user / application that created the control network
buffer_header_size : int
Total size of the header in bytes
points_bytes : int
The total number of bytes all points require
Returns
-------
: object
An ISIS compliant PVL header object
"""
encoder = pvl.encoder.IsisCubeLabelEncoder
header_bytes = buffer_header_size
points_start_byte = HEADERSTARTBYTE + buffer_header_size
header = pvl.PVLModule([(
'ProtoBuffer',
({
'Core': {
'HeaderStartByte': headerstartbyte,
'HeaderBytes': header_bytes,
'PointsStartByte': points_start_byte,
'PointsBytes': points_bytes
},
'ControlNetworkInfo':
pvl.PVLGroup([('NetworkId', networkid),
('TargetName', targetname),
('UserName', username),
('Created', creation_date),
('LastModified', modified_date),
('Description', description),
('NumberOfPoints', self.npoints),
('NumberOfMeasures', self.nmeasures),
('Version', version)])
}),
)])
return pvl.dumps(header, cls=encoder)
def test_quoated_strings():
module = pvl.PVLModule([
('int_like', "123"),
('float_like', '.2'),
('date', '1987-02-25'),
('time', '03:04:05'),
('datetime', '1987-02-25T03:04:05'),
('keyword', 'END'),
('restricted_chars', '&<>\'{},[]=!#()%";|'),
('restricted_seq', '/**/'),
])
assert module == pvl.loads(pvl.dumps(module))
encoder = pvl.encoder.IsisCubeLabelEncoder
assert module == pvl.loads(pvl.dumps(module, cls=encoder))
encoder = pvl.encoder.PDSLabelEncoder
assert module == pvl.loads(pvl.dumps(module, cls=encoder))
def test_quoated_strings():
module = pvl.PVLModule([
('int_like', "123"),
('float_like', '.2'),
('date', '1987-02-25'),
('time', '03:04:05'),
('datetime', '1987-02-25T03:04:05'),
('keyword', 'END'),
('restricted_chars', '&<>\'{},[]=!#()%";|'),
('restricted_seq', '/**/'),
])
assert module == pvl.loads(pvl.dumps(module))
encoder = pvl.encoder.IsisCubeLabelEncoder
assert module == pvl.loads(pvl.dumps(module, cls=encoder))
encoder = pvl.encoder.PDSLabelEncoder
assert module == pvl.loads(pvl.dumps(module, cls=encoder))
def Map2File(self, filename):
"""
Parameters
----------
filename
"""
self.mapDICT['End_Group'] = 'Mapping'
tempPVL = pvl.dumps(self.mapDICT)
with open(filename, 'wb') as f:
f.write(tempPVL)
def test_dumps_PDS(self):
s = '''A = b\r
GROUP = staygroup\r
C = d\r
END_GROUP = staygroup\r
OBJECT = obj\r
D = e\r
GROUP = f\r
G = h\r
END_GROUP = f\r
END_OBJECT = obj\r
END\r\n'''
self.assertEqual(s, pvl.dumps(self.module))
def Map2pvl(self):
"""
Returns
----------
str
mappvl
"""
self.mapDICT['End_Group'] = 'Mapping'
mappvl = pvl.dumps(self.mapDICT)
self.mappvl = mappvl
return mappvl
def Map2pvl(self):
"""
Returns
----------
str
mappvl
"""
self.mapDICT['End_Group'] = 'Mapping'
mappvl = pvl.dumps(self.mapDICT, encoder=pvl.encoder.ISISEncoder())
self.mappvl = mappvl
return mappvl
def test_dumps_PVL(self):
s = '''a = b;
BEGIN_GROUP = staygroup;
c = d;
END_GROUP = staygroup;
BEGIN_GROUP = obj;
d = e;
BEGIN_GROUP = f;
g = h;
END_GROUP = f;
END_GROUP = obj;
END;'''
self.assertEqual(
s, pvl.dumps(self.module, encoder=pvl.encoder.PVLEncoder()))
def test_quoated_strings():
module = pvl.PVLModule([
("int_like", "123"),
("float_like", ".2"),
("date", "1987-02-25"),
("time", "03:04:05"),
("datetime", "1987-02-25T03:04:05"),
("keyword", "END"),
# both kinds of quotes aren't allowed:
# ('restricted_chars', '&<>\'{},[]=!#()%";|'),
("restricted_chars", '&<>{},[]=!#()%";|'),
("restricted_seq", "/**/"),
])
assert module == pvl.loads(
pvl.dumps(module, encoder=pvl.encoder.PVLEncoder()))
def test_special_values():
module = pvl.PVLModule([
("bool_true", True),
("bool_false", False),
("null", None),
])
assert module == pvl.loads(
pvl.dumps(module, encoder=pvl.encoder.PVLEncoder()))
# IsisCubeLabelEncoder class is deprecated
# encoder = pvl.encoder.IsisCubeLabelEncoder
# assert module == pvl.loads(pvl.dumps(module, cls=encoder))
# This is now the default:
# encoder = pvl.encoder.PDSLabelEncoder
# But to compare with PVL written by the PDSLabelEncoder, the
# labels must be uppercase:
pds_module = pvl.PVLModule([
("BOOL_TRUE", True),
("BOOL_FALSE", False),
("NULL", None),
])
assert pds_module == pvl.loads(pvl.dumps(module))
def test_quoated_strings():
module = pvl.PVLModule([
('int_like', "123"),
('float_like', '.2'),
('date', '1987-02-25'),
('time', '03:04:05'),
('datetime', '1987-02-25T03:04:05'),
('keyword', 'END'),
# both kinds of quotes aren't allowed:
# ('restricted_chars', '&<>\'{},[]=!#()%";|'),
('restricted_chars', '&<>{},[]=!#()%";|'),
('restricted_seq', '/**/'),
])
assert module == pvl.loads(
pvl.dumps(module, encoder=pvl.encoder.PVLEncoder()))
def test_dumps_ODL(self):
s = '''A = b\r
GROUP = staygroup\r
C = d\r
END_GROUP = staygroup\r
GROUP = obj\r
D = e\r
GROUP = f\r
G = h\r
END_GROUP = f\r
END_GROUP = obj\r
END\r\n'''
self.assertEqual(
s, pvl.dumps(self.module, encoder=pvl.encoder.ODLEncoder()))
def default(self, obj):
if isinstance(obj, np.ndarray):
return obj.tolist()
if isinstance(obj, np.int64):
return int(obj)
if isinstance(obj, datetime.datetime):
return obj.__str__()
if isinstance(obj, bytes):
return obj.decode("utf-8")
if isinstance(obj, pvl.PVLModule):
return pvl.dumps(obj)
if isinstance(obj, set):
return list(obj)
if isinstance(obj, np.nan):
return None
return json.JSONEncoder.default(self, obj)
def create_camera(obj,
url='http://pfeffer.wr.usgs.gov/v1/pds/',
plugin_name='USGS_ASTRO_LINE_SCANNER_PLUGIN',
model_name='USGS_ASTRO_LINE_SCANNER_SENSOR_MODEL'):
data = data_from_cube(obj.metadata)
data_serialized = {'label': pvl.dumps(data).decode()}
r = requests.post(url, json=data_serialized).json()
r['IKCODE'] = -1
# Get the ISD back and instantiate a local ISD for the image
isd = csmapi.Isd.loads(r)
# Create the plugin and camera as usual
plugin = csmapi.Plugin.findPlugin(plugin_name)
if plugin.canModelBeConstructedFromISD(isd, model_name):
return plugin.constructModelFromISD(isd, model_name)
def _update_label(self, label, array):
"""Update PDS3 label for NumPy Array.
It is called by '_create_label' to update label values
such as,
- ^IMAGE, RECORD_BYTES
- STANDARD_DEVIATION
- MAXIMUM, MINIMUM
- MEDIAN, MEAN
Returns
-------
Update label module for the NumPy array.
Usage: self.label = self._update_label(label, array)
"""
maximum = float(numpy.max(array))
mean = float(numpy.mean(array))
median = float(numpy.median(array))
minimum = float(numpy.min(array))
stdev = float(numpy.std(array, ddof=1))
encoder = pvl.encoder.PDSLabelEncoder
serial_label = pvl.dumps(label, cls=encoder)
label_sz = len(serial_label)
image_pointer = int(label_sz / label['RECORD_BYTES']) + 1
label['^IMAGE'] = image_pointer + 1
label['LABEL_RECORDS'] = image_pointer
label['IMAGE']['MEAN'] = mean
label['IMAGE']['MAXIMUM'] = maximum
label['IMAGE']['MEDIAN'] = median
label['IMAGE']['MINIMUM'] = minimum
label['IMAGE']['STANDARD_DEVIATION'] = stdev
return label
def _update_label(self, label, array):
"""Update PDS3 label for NumPy Array.
It is called by '_create_label' to update label values
such as,
- ^IMAGE, RECORD_BYTES
- STANDARD_DEVIATION
- MAXIMUM, MINIMUM
- MEDIAN, MEAN
Returns
-------
Update label module for the NumPy array.
Usage: self.label = self._update_label(label, array)
"""
maximum = float(numpy.max(array))
mean = float(numpy.mean(array))
median = float(numpy.median(array))
minimum = float(numpy.min(array))
stdev = float(numpy.std(array, ddof=1))
encoder = pvl.encoder.PDSLabelEncoder
serial_label = pvl.dumps(label, cls=encoder)
label_sz = len(serial_label)
image_pointer = int(label_sz / label['RECORD_BYTES']) + 1
label['^IMAGE'] = image_pointer + 1
label['LABEL_RECORDS'] = image_pointer
label['IMAGE']['MEAN'] = mean
label['IMAGE']['MAXIMUM'] = maximum
label['IMAGE']['MEDIAN'] = median
label['IMAGE']['MINIMUM'] = minimum
label['IMAGE']['STANDARD_DEVIATION'] = stdev
return label
def test_default_encoder():
for filename in PDS_COMPLIANT:
label = pvl.load(filename)
assert label == pvl.loads(pvl.dumps(label))
def test_pds_encoder():
for filename in PDS_COMPLIANT:
label = pvl.load(filename)
encoder = pvl.encoder.PDSLabelEncoder()
assert label == pvl.loads(pvl.dumps(label, encoder=encoder))
async def _set_label(self, key: str, image: PDSImage) -> None:
label = await image.label
await super().set(f'{key}:label', pvl.dumps(label))
def test_unkown_value():
class UnknownType(object):
pass
with pytest.raises(TypeError):
print(pvl.dumps({"foo": UnknownType()}))
def test_unkown_value():
class UnknownType(object):
pass
with pytest.raises(TypeError):
pvl.dumps({'foo': UnknownType()})
async def download_label(request):
label = await image.label
body = pvl.dumps(label)
return aiohttp.web.Response(body=body)
def test_pds_encoder():
for filename in PDS_LABELS:
label = pvl.load(filename)
encoder = pvl.encoder.PDSLabelEncoder
assert label == pvl.loads(pvl.dumps(label, cls=encoder))
def test_pds_encoder():
for filename in PDS_LABELS:
label = pvl.load(filename)
encoder = pvl.encoder.PDSLabelEncoder
assert label == pvl.loads(pvl.dumps(label, cls=encoder))
def test_default_encoder():
for filename in PDS_LABELS:
label = pvl.load(filename)
assert label == pvl.loads(pvl.dumps(label))
def create_pvl_header(self, cnet, version, headerstartbyte,
networkid, targetname, description, username,
buffer_header_size, points_bytes):
"""
Create the PVL header object
Parameters
----------
cnet : object
A control net object
version : int
The current ISIS version to write, defaults to 2
headerstartbyte : int
The seek offset that the protocol buffer header starts at
networkid : str
The name of the network
targetname : str
The name of the target, e.g. Moon
description : str
A description for the network.
username : str
The name of the user / application that created the control network
buffer_header_size : int
Total size of the header in bytes
points_bytes : int
The total number of bytes all points require
Returns
-------
: object
An ISIS compliant PVL header object
"""
encoder = pvl.encoder.IsisCubeLabelEncoder
header_bytes = buffer_header_size
points_start_byte = HEADERSTARTBYTE + buffer_header_size
header = pvl.PVLModule([
('ProtoBuffer',
({'Core':{'HeaderStartByte': headerstartbyte,
'HeaderBytes': header_bytes,
'PointsStartByte': points_start_byte,
'PointsBytes': points_bytes},
'ControlNetworkInfo': pvl.PVLGroup([
('NetworkId', networkid),
('TargetName', targetname),
('UserName', username),
('Created', cnet.creationdate),
('LastModified', cnet.modifieddate),
('Description', description),
('NumberOfPoints', cnet.n),
('NumberOfMeasures', cnet.m),
('Version', version)
])
}),
)
])
return pvl.dumps(header, cls=encoder)