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[python #VOC-640241]: siphon filter_time_nearest : No datasets with times found

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  • Subject: [python #VOC-640241]: siphon filter_time_nearest : No datasets with times found
  • Date: Mon, 28 Sep 2020 21:53:37 -0600
Greetings!

Due to the way the grib collections are structured by the THREDDS Data Server, 
you need to use `.catalog_refs` rather than `.datasets`. So that code would 
work as:

    cat = TDSCatalog('http://thredds.ucar.edu/thredds/catalog/grib/'
                     'NCEP/GFS/Global_0p25deg/catalog.xml')

    # Find the run closest to 6 hours ago
    time = datetime.utcnow() - timedelta(hours=6)
    ds = cat.catalog_refs.filter_time_nearest(time)

    # Find all runs from the last day
    end = datetime.utcnow()
    start = end - timedelta(days=1)
    cat.catalog_refs.filter_time_range(start, end)

Also, if you're accessing model data, you just might be better off using the 
'Full Collection (Reference / Forecast Time) Dataset', 'Best GFS Quarter Degree 
Forecast Time Series', or 'Latest Collection for GFS Quarter Degree Forecast' 
datasets that *are* available within the `.datasets` attribute. You can also 
see them listed at the top of the catalog here:

  
https://thredds.ucar.edu/thredds/catalog/grib/NCEP/GFS/Global_0p25deg/catalog.html

Hope this helps,

Ryan

> Ryan !
> 
> I'm trying to get filter_time_nearest to work. I tried the code in
> https://www.unidata.ucar.edu/blogs/news/entry/siphon-0-5 (and changed
> "cat.filter_time_nearest(time)" to "cat.datasets.filter_time_nearest(time)"
> ), but I get "No datasets with times found".
> 
> Suggestions ?


Ticket Details
===================
Ticket ID: VOC-640241
Department: Support Python
Priority: Low
Status: Closed
===================
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