Define the filter delimiter in a single place

lsst · Feb 6, 2020 · 1ac5862 · 1ac5862
1 parent fb80d56
commit 1ac5862
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Showing 3 changed files with 9 additions and 6 deletions.
diff --git a/python/lsst/obs/lsst/filters.py b/python/lsst/obs/lsst/filters.py
@@ -22,6 +22,7 @@
 __all__ = ()
 
 from lsst.obs.base import FilterDefinition, FilterDefinitionCollection
+from .translators.lsst import FILTER_DELIMITER
 
 
 LSSTCAM_FILTER_DEFINITIONS = FilterDefinitionCollection(
@@ -79,7 +80,6 @@
 
 # Form a new set of filter definitions from all the explicit filters
 _latiss_gratings = ("ronchi90lpmm", "ronchi170lpmm", "EMPTY", "NONE")
-_delimiter = "~"
 
 # Include the filters without the grating in case someone wants
 # to retrieve a filter by an actual filter name
@@ -88,10 +88,10 @@
 for filter in _latiss_filters:
     for grating in _latiss_gratings:
         # FilterDefinition is a frozen dataclass
-        new_name = _delimiter.join([filter.physical_filter, grating])
+        new_name = FILTER_DELIMITER.join([filter.physical_filter, grating])
 
         # Also need to update aliases
-        new_aliases = {_delimiter.join([a, grating]) for a in filter.alias}
+        new_aliases = {FILTER_DELIMITER.join([a, grating]) for a in filter.alias}
 
         combo = FilterDefinition(physical_filter=new_name,
                                  lambdaEff=filter.lambdaEff,

diff --git a/python/lsst/obs/lsst/translators/latiss.py b/python/lsst/obs/lsst/translators/latiss.py
@@ -21,7 +21,7 @@
 
 from astro_metadata_translator import cache_translation
 from astro_metadata_translator.translators.helpers import is_non_science
-from .lsst import LsstBaseTranslator
+from .lsst import LsstBaseTranslator, FILTER_DELIMITER
 
 log = logging.getLogger(__name__)
 
@@ -434,7 +434,7 @@ def to_physical_filter(self):
         else:
             grating = "NONE"
 
-        physical_filter = f"{physical_filter}~{grating}"
+        physical_filter = f"{physical_filter}{FILTER_DELIMITER}{grating}"
 
         return physical_filter
 

diff --git a/python/lsst/obs/lsst/translators/lsst.py b/python/lsst/obs/lsst/translators/lsst.py
@@ -36,6 +36,9 @@
 TZERO = Time("2015-01-01T00:00", format="isot", scale="utc")
 TZERO_DATETIME = TZERO.to_datetime()
 
+# Delimiter to use for multiple filters/gratings
+FILTER_DELIMITER = "~"
+
 # Regex to use for parsing a GROUPID string
 GROUP_RE = re.compile(r"^(\d\d\d\d\-\d\d\-\d\dT\d\d:\d\d:\d\d)\.(\d\d\d)(?:[\+#](\d+))?$")
 
@@ -596,7 +599,7 @@ def to_physical_filter(self):
             Name of filter. Can be a combination of FILTER, FILTER1 and FILTER2
             headers joined by a "~".  Returns "NONE" if no filter is declared.
         """
-        joined = self._join_keyword_values(["FILTER", "FILTER1", "FILTER2"], delim="~")
+        joined = self._join_keyword_values(["FILTER", "FILTER1", "FILTER2"], delim=FILTER_DELIMITER)
         if not joined:
             joined = "NONE"