Handle metadata consistently. Work around astropy issues with None.

python/lsst/ip/isr/calibType.py

@@ -19,7 +19,6 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 import abc
-import copy
 import datetime
 import os.path
 import warnings
@@ -70,7 +69,7 @@ def __init__(self, camera=None, detector=None, detectorName=None, detectorId=Non
         self._detectorId = detectorId
         self._filter = None
         self._calibId = None
-
+        self._metadata = PropertyList()
         self.setMetadata(PropertyList())
 
         # Define the required attributes for this calibration.
@@ -133,7 +132,7 @@ def setMetadata(self, metadata):
             overwrite existing metadata.
         """
         if metadata is not None:
-            self._metadata = copy.copy(metadata)
+            self._metadata.update(metadata)
 
         # Ensure that we have the obs type required by calibration ingest
         self._metadata["OBSTYPE"] = self._OBSTYPE

python/lsst/ip/isr/crosstalk.py

@@ -368,8 +368,11 @@ def toTable(self):
                           'CT_COUNTS': self.coeffNum.reshape(self.nAmp*self.nAmp),
                           'CT_VALID': self.coeffValid.reshape(self.nAmp*self.nAmp),
                           }])
-
-        catalog.meta = self.getMetadata().toDict()
+        # filter None, because astropy can't deal.
+        inMeta = self.getMetadata().toDict()
+        outMeta = {k: v for k, v in inMeta.items() if v is not None}
+        outMeta.update({k: "" for k, v in inMeta.items() if v is None})
+        catalog.meta = outMeta
         tableList.append(catalog)
 
         if self.interChip: