added a method to retrieve all searchable columns names and their descriptions for a mission

Author: syed-gilani

astroquery/mast/missions.py

@@ -6,6 +6,8 @@
 This module contains methods for searching MAST missions.
 """
 
+import requests
+
 import astropy.units as u
 import astropy.coordinates as coord
 
@@ -16,6 +18,8 @@
 from astroquery.mast import utils
 from astroquery.mast.core import MastQueryWithLogin
 
+from . import conf
+
 __all__ = ['MastMissionsClass', 'MastMissions']
 
 
@@ -183,5 +187,28 @@ def query_object_async(self, objectname, radius=3*u.arcmin, **kwargs):
 
         return self.query_region_async(coordinates, radius, **kwargs)
 
+    @class_or_instance
+    def get_column_list(self):
+        """
+        For a mission, return a list of all searchable columns and their descriptions
+
+        Returns
+        -------
+        json data that contains columns names and their descriptions
+        """
+
+        url = f"{conf.server}/search/util/api/v0.1/column_list?mission={self.mission}"
+
+        try:
+            results = requests.get(url)
+            results = results.json()
+            for result in results:
+                result.pop('field_name')
+                result.pop('queryable')
+                result.pop('indexed')
+                result.pop('default_output')
+            return results
+        except:
+            raise Exception(f"Error occured while trying to get column list for mission {self.mission}")
 
 MastMissions = MastMissionsClass()