The numpy.equal function does not work if a list or array contains strings:

>>> import numpy
>>> index = numpy.equal([1,2,'a'],None)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: function not supported for these types, and can't coerce safely to supported types

What is the easiest way to workaround this without looping through each element? In the end, I need index to contain a boolean array indicating which elements are None.