`np.isnan(attr1)` produces the following error.
I think for that to work the array needs to be of the same data type.
`attr1` here is an array of scalars as well as other arrays
```python
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/home/vighnesh/git/scikit-image/skimage/measure/tests/test_regionprops.py", line 377, in test_equals
    assert r1 == r2
  File "/home/vighnesh/git/scikit-image/skimage/measure/_regionprops.py", line 339, in __eq__
    print np.isnan(attr1)
TypeError: ufunc 'isnan' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule ''safe''
```

The only change I can think of is not creating `attr1` as an array, and just use it as a list.