Don't import astropy stuff at module scope

astropy · Jan 28, 2025 · 4cd79ee · 4cd79ee
1 parent 1898456
commit 4cd79ee
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Showing 2 changed files with 8 additions and 16 deletions.
diff --git a/asdf_astropy/converters/coordinates/angle.py b/asdf_astropy/converters/coordinates/angle.py
@@ -1,19 +1,12 @@
-from astropy.coordinates.angles import Angle, Latitude, Longitude
-from astropy.utils.masked import Masked
-
 from asdf_astropy.converters.unit.quantity import QuantityConverter
 
-MaskedAngle = Masked(Angle)
-MaskedLatitude = Masked(Latitude)
-MaskedLongitude = Masked(Longitude)
-
 
 class AngleConverter(QuantityConverter):
     tags = ("tag:astropy.org:astropy/coordinates/angle-*",)
     types = (
         "astropy.coordinates.angles.Angle",
         "astropy.coordinates.angles.core.Angle",
-        MaskedAngle,
+        "astropy.utils.masked.core.MaskedAngle",
     )
 
     def from_yaml_tree(self, node, tag, ctx):
@@ -27,7 +20,7 @@ class LatitudeConverter(QuantityConverter):
     types = (
         "astropy.coordinates.angles.Latitude",
         "astropy.coordinates.angles.core.Latitude",
-        MaskedLatitude,
+        "astropy.utils.masked.core.MaskedLatitude",
     )
 
     def from_yaml_tree(self, node, tag, ctx):
@@ -41,7 +34,7 @@ class LongitudeConverter(QuantityConverter):
     types = (
         "astropy.coordinates.angles.Longitude",
         "astropy.coordinates.angles.core.Longitude",
-        MaskedLongitude,
+        "astropy.utils.masked.core.MaskedLongitude",
     )
 
     def to_yaml_tree(self, obj, tag, ctx):

diff --git a/asdf_astropy/converters/unit/quantity.py b/asdf_astropy/converters/unit/quantity.py
@@ -1,10 +1,5 @@
-import numpy as np
 from asdf.extension import Converter
 from asdf.tags.core.ndarray import NDArrayType
-from astropy.units import Quantity
-from astropy.utils.masked import Masked
-
-MaskedQuantity = Masked(Quantity)
 
 
 class QuantityConverter(Converter):
@@ -14,10 +9,13 @@ class QuantityConverter(Converter):
         # The Distance class has no tag of its own, so we
         # just serialize it as a quantity.
         "astropy.coordinates.distances.Distance",
-        MaskedQuantity,
+        "astropy.utils.masked.core.MaskedQuantity",
     )
 
     def to_yaml_tree(self, obj, tag, ctx):
+        import numpy as np
+        from astropy.utils.masked import Masked
+
         node = {
             "value": np.ma.asarray(obj.value) if isinstance(obj, Masked) else obj.value,
             "unit": obj.unit,
@@ -34,6 +32,7 @@ def from_yaml_tree(self, node, tag, ctx):
         # astropy 6.1 changed Quantity in a similar way
         import numpy as np
         from astropy.units import Quantity
+        from astropy.utils.masked.core import MaskedQuantity
 
         copy = None if np.lib.NumpyVersion(np.__version__) >= "2.0.0b1" else False