Merge pull request #541 from bsipocz/sdss_add_no_result_found_message

Check whether no result is returned from the query (SDSS)

Author: keflavich

astroquery/besancon/core.py

@@ -6,9 +6,9 @@
 import sys
 import re
 import os
+import warnings
 from astropy.io import ascii
 from astropy.extern.six.moves.urllib_error import URLError
-from astropy.extern.six import StringIO
 from collections import OrderedDict
 from ..query import BaseQuery
 from ..utils import commons
@@ -428,9 +428,10 @@ def parse_besancon_model_string(bms,):
 
     for cn in besancon_table.columns:
         if besancon_table[cn].dtype.kind in ('s', 'S'):
-            print("WARNING: The Besancon table did not parse properly.  "
-                  "Some columns are likely to have invalid values and others incorrect values.  "
-                  "Please report this error.")
+            warnings.warn("The Besancon table did not parse properly.  "
+                          "Some columns are likely to have invalid "
+                          "values and others incorrect values.  "
+                          "Please report this error.")
             break
 
     return besancon_table

astroquery/cosmosim/core.py

@@ -15,7 +15,7 @@
 from astropy.table import Table, Column
 from astropy import log
 
-from ..exceptions import LoginError, RemoteServiceError
+from ..exceptions import LoginError, RemoteServiceError, NoResultsWarning
 from ..utils import schema, system_tools
 from ..query import QueryWithLogin, suspend_cache
 from . import conf
@@ -283,7 +283,7 @@ def query_survey(self, survey, cache=True, **kwargs):
                     raise ex
             return table
         else:
-            warnings.warn("Query returned no results")
+            warnings.warn("Query returned no results", NoResultsWarning)
 
     def query_instrument(self, instrument, column_filters={}, columns=[],
                          open_form=False, help=False, cache=True, **kwargs):
@@ -366,8 +366,7 @@ def query_instrument(self, instrument, column_filters={}, columns=[],
                         raise ex
                 return table
             else:
-                warnings.warn("Query returned no results")
-
+                warnings.warn("Query returned no results", NoResultsWarning)
 
     def get_headers(self, product_ids, cache=True):
         """

astroquery/eso/core.py

@@ -3,8 +3,10 @@
 Custom exceptions used in the astroquery query classes
 """
 
+from astropy.utils.exceptions import AstropyWarning
+
 __all__ = ['TimeoutError', 'InvalidQueryError', 'RemoteServiceError',
-           'TableParseError', 'LoginError']
+           'TableParseError', 'LoginError', 'NoResultsWarning']
 
 
 class TimeoutError(Exception):
@@ -43,3 +45,9 @@ class LoginError(Exception):
     a login is a prerequisite for the requested action
     """
     pass
+
+
+class NoResultsWarning(AstropyWarning):
+    """
+    Astroquery warning class to be issued when a query returns no result.
+    """

astroquery/exceptions.py

@@ -101,7 +101,7 @@
 from ..query import BaseQuery
 from ..utils import commons
 from . import conf
-from ..exceptions import TableParseError
+from ..exceptions import TableParseError, NoResultsWarning
 
 __all__ = ['Irsa', 'IrsaClass']
 
@@ -365,7 +365,8 @@ def _parse_result(self, response, verbose=False):
 
         # Check if table is empty
         if len(table) == 0:
-            warnings.warn("Query returned no results, so the table will be empty")
+            warnings.warn("Query returned no results, so the table will "
+                          "be empty", NoResultsWarning)
 
         return table
 

astroquery/irsa/core.py

@@ -57,10 +57,10 @@
 
 order       Optional    Results ordered by this column.
 
-selcols     Optional    Select specific columns to be returned. The default 
-                        action is to return all columns in the queried catalog. 
-                        To find the names of the columns in the LCOGT Archive databases, 
-                        please read Photometry Table column descriptions [http://lcogtarchive.ipac.caltech.edu/docs/lco_cat_dd.html] 
+selcols     Optional    Select specific columns to be returned. The default
+                        action is to return all columns in the queried catalog.
+                        To find the names of the columns in the LCOGT Archive databases,
+                        please read Photometry Table column descriptions [http://lcogtarchive.ipac.caltech.edu/docs/lco_cat_dd.html]
                         and Image Table column descriptions [http://lcogtarchive.ipac.caltech.edu/docs/lco_img_dd.html].
 
 constraint  Optional    User defined query constraint(s)
@@ -70,7 +70,6 @@
 from __future__ import print_function, division
 
 import warnings
-import xml.etree.ElementTree as tree
 import logging
 
 from astropy.extern import six
@@ -81,7 +80,7 @@
 from ..query import BaseQuery
 from ..utils import commons, async_to_sync
 from . import conf
-from ..exceptions import TableParseError
+from ..exceptions import TableParseError, NoResultsWarning
 
 __all__ = ['Lcogt', 'LcogtClass']
 
@@ -347,7 +346,8 @@ def _parse_result(self, response, verbose=False):
 
         # Check if table is empty
         if len(table) == 0:
-            warnings.warn("Query returned no results, so the table will be empty")
+            warnings.warn("Query returned no results, so the table will "
+                          "be empty", NoResultsWarning)
 
         return table
 

astroquery/lcogt/core.py

@@ -11,6 +11,7 @@
 
 from __future__ import print_function
 import io
+import warnings
 import numpy as np
 from astropy import units as u
 import astropy.coordinates as coord
@@ -19,7 +20,7 @@
 from . import conf
 from ..utils import commons, async_to_sync
 from ..utils.docstr_chompers import prepend_docstr_noreturns
-from ..exceptions import RemoteServiceError
+from ..exceptions import RemoteServiceError, NoResultsWarning
 
 __all__ = ['SDSS', 'SDSSClass']
 
@@ -513,9 +514,12 @@ def get_spectra_async(self, coordinates=None, radius=2. * u.arcsec,
             r = commons.send_request(SDSS.QUERY_URL, request_payload, timeout,
                                      request_type='GET')
             matches = self._parse_result(r)
+            if matches is None:
+                warnings.warn("Query returned no results.", NoResultsWarning)
+                return
 
         if not isinstance(matches, Table):
-            raise TypeError("Matches must be an astropy Table.")
+            raise TypeError("'matches' must be an astropy Table.")
 
         results = []
         for row in matches:
@@ -549,7 +553,11 @@ def get_spectra(self, coordinates=None, radius=2. * u.arcsec,
                                                plate=plate, fiberID=fiberID,
                                                mjd=mjd, timeout=timeout)
 
-        return [obj.get_fits() for obj in readable_objs]
+        if readable_objs is not None:
+            if isinstance(readable_objs, dict):
+                return readable_objs
+            else:
+                return [obj.get_fits() for obj in readable_objs]
 
     def get_images_async(self, coordinates=None, radius=2. * u.arcsec,
                          matches=None, run=None, rerun=301, camcol=None,
@@ -640,9 +648,11 @@ def get_images_async(self, coordinates=None, radius=2. * u.arcsec,
             r = commons.send_request(SDSS.QUERY_URL, request_payload, timeout,
                                      request_type='GET')
             matches = self._parse_result(r)
-
+            if matches is None:
+                warnings.warn("Query returned no results.", NoResultsWarning)
+                return
         if not isinstance(matches, Table):
-            raise ValueError
+            raise ValueError("'matches' must be an astropy Table")
 
         results = []
         for row in matches:
@@ -665,7 +675,8 @@ def get_images_async(self, coordinates=None, radius=2. * u.arcsec,
     @prepend_docstr_noreturns(get_images_async.__doc__)
     def get_images(self, coordinates=None, radius=2. * u.arcsec,
                    matches=None, run=None, rerun=301, camcol=None, field=None,
-                   band='g', timeout=TIMEOUT, cache=True):
+                   band='g', timeout=TIMEOUT, cache=True,
+                   get_query_payload=False):
         """
         Returns
         -------
@@ -678,9 +689,13 @@ def get_images(self, coordinates=None, radius=2. * u.arcsec,
                                               run=run, rerun=rerun,
                                               camcol=camcol, field=field,
                                               band=band, timeout=timeout,
-                                              get_query_payload=False)
+                                              get_query_payload=get_query_payload)
 
-        return [obj.get_fits() for obj in readable_objs]
+        if readable_objs is not None:
+            if isinstance(readable_objs, dict):
+                return readable_objs
+            else:
+                return [obj.get_fits() for obj in readable_objs]
 
     def get_spectral_template_async(self, kind='qso', timeout=TIMEOUT):
         """
@@ -744,7 +759,8 @@ def get_spectral_template(self, kind='qso', timeout=TIMEOUT):
         readable_objs = self.get_spectral_template_async(kind=kind,
                                                          timeout=timeout)
 
-        return [obj.get_fits() for obj in readable_objs]
+        if readable_objs is not None:
+            return [obj.get_fits() for obj in readable_objs]
 
     def _parse_result(self, response, verbose=False):
         """
@@ -831,7 +847,7 @@ def _args_to_payload(self, coordinates=None, radius=2. * u.arcsec,
             SpecObj quantities to return. If photoobj_fields is None and
             specobj_fields is None then the value of fields is used
         field_help: str or bool, optional
-            Field name to check whether a valid PhotoObjAll or SpecObjAll
+            Field name to check whether it is a valid PhotoObjAll or SpecObjAll
             field name. If `True` or it is an invalid field name all the valid
             field names are returned as a dict.
         obj_names : str, or list or `~astropy.table.Column`, optional
@@ -857,9 +873,9 @@ def _args_to_payload(self, coordinates=None, radius=2. * u.arcsec,
                 return
             else:
                 if field_help is not True:
-                    print("{0} isn't a valid 'photobj_field' or "
-                          "'specobj_field' field, valid fields are "
-                          "returned.".format(field_help))
+                    warnings.warn("{0} isn't a valid 'photobj_field' or "
+                                  "'specobj_field' field, valid fields are"
+                                  "returned.".format(field_help))
                 return {'photoobj_all': photoobj_all,
                         'specobj_all': specobj_all}
 

astroquery/sdss/core.py

@@ -14,7 +14,7 @@
 import astropy.io.votable as votable
 
 from ..query import QueryWithLogin
-from ..exceptions import InvalidQueryError, TimeoutError
+from ..exceptions import InvalidQueryError, TimeoutError, NoResultsWarning
 from ..utils import commons
 from . import conf
 from ..exceptions import TableParseError
@@ -549,7 +549,8 @@ def _parse_result(self, response, verbose=False):
             first_table = parsed_table.get_first_table()
             table = first_table.to_table()
             if len(table) == 0:
-                warnings.warn("Query returned no results, so the table will be empty")
+                warnings.warn("Query returned no results, so the table will "
+                              "be empty", NoResultsWarning)
             return table
         except Exception as ex:
             self.response = content
@@ -559,7 +560,6 @@ def _parse_result(self, response, verbose=False):
                                   "in self.response, and the error in self.table_parse_error.  "
                                   "Exception: " + str(self.table_parse_error))
 
-
     def list_catalogs(self, style='short'):
         """
         Returns a list of available catalogs in UKIDSS.