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Cannot sort table by Time column #10823
Description
Description
I have a Table with a column containing Time objects. I want to sort the rows by that column with Time objects. I get AttributeError: 'Time' object has no attribute 'view' error. Same error using QTable.
I found #8068 but in that issue, the sort wasn't done with the Time column even though the table contains a Time column.
Expected behavior
Table successfully sorted in-place by ascending Time order.
Actual behavior
Unsuccessful operation with AttributeError: 'Time' object has no attribute 'view' error.
Steps to Reproduce
>>> from astropy.table import Table
>>> from astropy.time import Time
>>> myrows = [('first row', Time('2001-01-01')), ('second row', Time('1980-12-31'))]
>>> tab = Table(rows=myrows, names=('a', 'b'))
>>> tab.sort('a') # No error
>>> tab.sort('b') # Traceback below.../astropy/table/table.py in sort(self, keys, reverse)
2960 keys = [keys]
2961
-> 2962 indexes = self.argsort(keys)
2963
2964 if reverse:
.../astropy/table/table.py in argsort(self, keys, kind, reverse)
2892 data = self.as_array(names=keys)
2893 else:
-> 2894 data = self[keys[0]].view(np.ndarray)
2895 else:
2896 # No keys provided so sort on all columns.
.../astropy/time/core.py in __getattr__(self, attr)
1341 else:
1342 # Should raise AttributeError
-> 1343 return self.__getattribute__(attr)
1344
1345 @override__dir__
AttributeError: 'Time' object has no attribute 'view'
System Details
Linux-3.10.0-1127.19.1.el7.x86_64-x86_64-with-glibc2.10
Python 3.8.3 (default, May 19 2020, 18:47:26)
[GCC 7.3.0]
Numpy 1.19.1
astropy 4.2.dev687+g214a599c1
Scipy 1.5.1
Matplotlib 3.3.1
Activity
pllim commentedon Oct 9, 2020
Workaround is to do
Time(...).strftime('%Y-%m-%d')and then sort the string.mhvk commentedon Oct 9, 2020
Hmm, this looks like a regression - this worked in 4.0! It is strange since
Timedoes have anargsortmethod.mhvk commentedon Oct 9, 2020
So another work-around is
mhvk commentedon Oct 9, 2020
The fix turns out to be fairly easy - PR forthcoming...
mhvk commentedon Oct 9, 2020
See #10824
pllim commentedon Oct 17, 2020
Thanks, all!