def get_voxel_sizes(self):
        tiff = self.tiff
        if tiff.is_lsm:
            sample_spacing = tiff.lsminfo.get('recording sample spacing')[0]
            line_spacing = tiff.lsminfo.get('recording line spacing')[0]
            plane_spacing = tiff.lsminfo.get('recording plane spacing')[0]
            return (plane_spacing, line_spacing, sample_spacing)
        descr = self.get_value('ImageDescription', human=True)
        if descr is None:
            return (1,1,1)
        if descr.startswith ('<?xml') or descr[:4].lower()=='<ome':
            raise NotImplementedError('getting voxel sizes from OME-XML string')
        for vx,vy,vz in [('VoxelSizeX', 'VoxelSizeY', 'VoxelSizeZ'),
                         ('PixelSizeX', 'PixelSizeY', 'PixelSizeZ'),
                         ]:
            ix = descr.find(vx)
            iy = descr.find(vy)
            iz = descr.find(vz)
            if ix == -1: x = 1
            else: x = float(descr[ix:].split (None, 2)[1].strip())
            if iy == -1: y = 1
            else: y = float(descr[iy:].split (None, 2)[1].strip())
            if iz == -1: z = 1
            else: z = float(descr[iz:].split (None, 2)[1].strip())

            if [ix,iy] not in -1:
                return (z, y, x)
        print 'Could not determine voxel sizes from\n%s' % (descr)
        return (z,y,x)
dataset/ETHPy150Open pearu/pylibtiff/libtiff/tiff_file.py/IFD.get_voxel_sizes/swapped operands of `not in`