AttributeError: 'HeasarcClass' object has no attribute '_last_catalog_name'

Helpdesk Data Access
1

I roughly was following instructions from NuSTAR tutorial notebook to download some obsids in XMM and I am running into the following problem. Let me know if there was a better place to ask this python heasarc related question

from astroquery.heasarc import Heasarc

xmm_table = heasarc.query_region(catalog=‘xmmmaster’, spatial=‘all-sky’)

mask = np.where(xmm_table[‘obsid’]==‘0900280101’)
data = xmm_table[mask] ## table of length 1

links = Heasarc.locate_data(data)

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Cell In[36], line 1
----> 1 links = Heasarc.locate_data(data)

File /opt/envs/sas/lib/python3.12/site-packages/astroquery/heasarc/core.py:511, in HeasarcClass.locate_data(self, query_result, catalog_name)
    506     raise ValueError('No __row column found in query_result. '
    507                      'query_result needs to be the output of '
    508                      'query_region or a subset.')
    510 if catalog_name is None:
--> 511     catalog_name = self._last_catalog_name
    512 if not (
    513     isinstance(catalog_name, str)
    514     and catalog_name in self.tap.tables.keys()
    515 ):
    516     raise ValueError(f'Unknown catalog name: {catalog_name}')

AttributeError: 'HeasarcClass' object has no attribute '_last_catalog_name'
3

The code you posted should work:

from astroquery.heasarc import Heasarc
xmm_table = Heasarc.query_region(catalog='xmmmaster', spatial='all-sky')
data = xmm_table[xmm_table['obsid']=='0900280101'] 
links = Heasarc.locate_data(data)

We recently made some updates that make the above done in a more efficient way. The updates are in the pre-released version of astroquery ((0.4.12)), which you can install by doing: !pip install astroquery --upgrade --pre in you notebook). You can then do:

from astroquery.heasarc import Heasarc
xmm_table = Heasarc.query_region(catalog='xmmmaster', column_filters={'obsid': '0900280101'})
links = Heasarc.locate_data(xmm_table)

# or with a list
xmm_table = Heasarc.query_region(catalog='xmmmaster', column_filters={'obsid': ['0606321501', '0606321601']})
4

Today after refreshing the server this works, but I have seen this error appear a few times already when I was doing the above call in a notebook with lots of other work. I will try to provide more details next time it appears if it does.

5

Thanks for reporting this - its quite an odd problem.

So you re-tried it this morning, without changing any versions of Astroquery, and it worked this time?

Are you using your own custom environment, or one of the built in ones?

6

This was all in sas environment but before I encountered it in the default one whatever it was. It’s usually as I said once I’ve been doing a lot of things and not starting “fresh”.

I will try to pin it down more, though I might not be needing to download things for a while.

7

The error can happen if multiple queries are made to different tables, or if locate_data is called before query_region. In that case, you may need to explicitly pass the catalog name to locate_data. So in the above case, it is:

links = Heasarc.locate_data(data, catalog_name='xmmmaster')

In the latest version of astroquery (0.4.12; not released yet), the error is clearer and tells you to pass catalog_name if it cannot figure it out.

8

Ok, I think this likely was the case!