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Combining label and boolean/value filter is super annoying #1084
Description
>>> arr = ndtest((2, 4))
>>> arr
a\b b0 b1 b2 b3
a0 0 1 2 3
a1 4 5 6 7
>>> arr[arr > 2, 'b0,b2,b3']
ValueError: key has several values for axis: b
key: (a.i[a_b a0_b3 a1_b0 a1_b1 a1_b2 a1_b3
0 1 1 1 1], b.i[a_b a0_b3 a1_b0 a1_b1 a1_b2 a1_b3
3 0 1 2 3], 'b0,b2,b3')The problem is that (contrary to #246), the boolean filter has the axis, of the label filter.
The workaround is to use boolean filters all the way:
>>> arr[(arr > 2) & ((arr.b == 'b0') | (arr.b == 'b2') | (arr.b == 'b3'))] = 42
>>> arr
a\b b0 b1 b2 b3
a0 0 1 2 42
a1 42 5 42 42The question is whether we want to make it work out of the box:
>>> arr[arr > 2, 'b0,b2,b3'] = 42
>>> arr
a\b b0 b1 b2 b3
a0 0 1 2 42
a1 42 5 42 42FWIW, for a single label, I find the workaround(s) is much more bearable:
>>> arr = ndtest((2, 4))
>>> arr[arr > 2, 'b0'] = 42
ValueError: key has several values for axis: b
key: (a.i[a_b a0_b3 a1_b0 a1_b1 a1_b2 a1_b3
0 1 1 1 1], b.i[a_b a0_b3 a1_b0 a1_b1 a1_b2 a1_b3
3 0 1 2 3], 'b0')
>>> arr[(arr > 2) & (arr.b == 'b0')] = 42
>>> arr
a\b b0 b1 b2 b3
a0 0 1 2 3
a1 42 5 6 7>>> arr = ndtest((2, 4))
>>> sub = arr['b0']
>>> sub[sub > 2] = 42
>>> arr
a\b b0 b1 b2 b3
a0 0 1 2 3
a1 42 5 6 7FWIW, the other work-around, which is taking a subset of the filter does not work either (and it is also broken, see issue #1085):
>>> arr = ndtest((2, 4))
>>> arr
>>> f = arr > 2
a\b b0 b1 b2 b3
a0 False False False True
a1 True True True True
>>> f['b0,b2,b3']
a\b b0 b2 b3
a0 False False True
a1 True True True
>>> arr['b0,b2,b3', f['b0,b2,b3']]
ValueError: key has several values for axis: bFor getting the values, we can successfully workaround it by doing it in two steps AND taking a subset of the filter:
>>> arr['b0,b2,b3'][f['b0,b2,b3']]
a_b a0_b3 a1_b0 a1_b2 a1_b3
3 4 6 7But this does not work for setting values though (because we are setting values on a temporary copy):
>>> arr = ndtest((2, 4))
>>> arr['b0,b2,b3'][f['b0,b2,b3']] = 42
>>> arr
a\b b0 b1 b2 b3
a0 0 1 2 3
a1 4 5 6 7
Activity
[-]Combining label and value filter is super annoying[/-][+]Combining label and boolean/value filter is super annoying[/+]