In [23]: from io import StringIO

In [24]: import numpy as np

In [25]: point = np.dtype([('x', float), ('y', float)])

In [26]: dt = np.dtype([('code', int), ('points', point, (2,))])

In [27]: dt
Out[27]: dtype([('code', '<i8'), ('points', [('x', '<f8'), ('y', '<f8')], (2,))])

In [28]: np.loadtxt(StringIO('100 1 2 3 4\n200 5 6 7 8\n'), dtype=dt)                                                     
Out[28]: 
array([(100, [(1., 1.), (2., 2.)]), (200, [(5., 5.), (6., 6.)])],
      dtype=[('code', '<i8'), ('points', [('x', '<f8'), ('y', '<f8')], (2,))])