[Numpy-discussion] Usage of numpy.where and pylab.find with strings

[Ariel Rokem]

Hi - I am trying to find a string in a list with strings and have come  
across the following state of affairs:

In [228]: subjects
Out[228]:
['KAA',
  'CCS',
  'EJS',
  'MNM',
  'JHS',
  'LJL',
  'DVA',
  'FCL',
  'CNC',
  'KFM',
  'APM',
  'GMC']

In [229]: subjects[0]
Out[229]: 'KAA'

In [230]: subjects[0] == 'KAA'
Out[230]: True

In [231]: np.where(subjects == 'KAA')
Out[231]: ()

In [232]: pylab.find(subjects == 'KAA')
Out[232]: array([], dtype=int32)

It doesn't seem to matter if I make the list into an array:

In [233]: np.array(subjects)
Out[233]:
array(['KAA', 'CCS', 'EJS', 'MNM', 'JHS', 'LJL', 'DVA', 'FCL', 'CNC',
        'KFM', 'APM', 'GMC'],
       dtype='|S3')

In [234]: pylab.find(subjects == 'KAA')
Out[234]: array([], dtype=int32)

In [235]: np.where(subjects == 'KAA')
Out[235]: ()

What am I doing wrong? What does it mean that the dtype is IS3?

Thanks a bunch --

Ariel

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