Merge pull request #3039 from bsipocz/BUG_handling_optional_regions

BUG: better handling the optional dependency required for functionality

astroquery/alma/core.py

@@ -218,6 +218,7 @@ def get_enhanced_table(result):
         print(
             "Could not import astropy-regions, which is a requirement for get_enhanced_table function in alma."
             "Please refer to http://astropy-regions.readthedocs.io/en/latest/installation.html for how to install it.")
+        raise
 
     def _parse_stcs_string(input):
         csys = 'icrs'

astroquery/alma/tests/test_alma_remote.py

@@ -16,6 +16,13 @@
 from astroquery.exceptions import CorruptDataWarning
 from astroquery.alma import Alma, get_enhanced_table
 
+try:
+    import regions
+
+    HAS_REGIONS = True
+except ImportError:
+    HAS_REGIONS = False
+
 # ALMA tests involving staging take too long, leading to travis timeouts
 # TODO: make this a configuration item
 SKIP_SLOW = True
@@ -62,11 +69,10 @@ def test_public(self, alma):
         for row in results:
             assert row['data_rights'] == 'Proprietary'
 
+    @pytest.mark.skipif(not HAS_REGIONS, reason="regions is required")
     @pytest.mark.filterwarnings(
         "ignore::astropy.utils.exceptions.AstropyUserWarning")
     def test_s_region(self, alma):
-        pytest.importorskip('regions')
-        import regions  # to silence checkstyle
         alma.help_tap()
         result = alma.query_tap("select top 3 s_region from ivoa.obscore")
         enhanced_result = get_enhanced_table(result)
@@ -75,6 +81,7 @@ def test_s_region(self, alma):
                                                 regions.PolygonSkyRegion,
                                                 regions.CompoundSkyRegion))
 
+    @pytest.mark.skipif(not HAS_REGIONS, reason="regions is required")
     @pytest.mark.filterwarnings(
         "ignore::astropy.utils.exceptions.AstropyUserWarning")
     def test_SgrAstar(self, tmp_path, alma):