text: from __future__ import division, absolute_import, print_function
  
  import sys
  
  import numpy as np
  from numpy.compat import asbytes, unicode, sixu
  from numpy.testing import (
      TestCase, run_module_suite, assert_, assert_equal, assert_array_equal)
  
  # Guess the UCS length for this python interpreter
  if sys.version_info[:2] >= (3, 3):
      # Python 3.3 uses a flexible string representation
      ucs4 = False
  
      def buffer_length(arr):
          if isinstance(arr, unicode):
              arr = str(arr)
              return (sys.getsizeof(arr+"a") - sys.getsizeof(arr)) * len(arr)
          v = memoryview(arr)
          if v.shape is None:
              return len(v) * v.itemsize
          else:
              return np.prod(v.shape) * v.itemsize
  else:
      if len(buffer(sixu('u'))) == 4:
          ucs4 = True
      else:
          ucs4 = False
  
      def buffer_length(arr):
          if isinstance(arr, np.ndarray):
              return len(arr.data)
          return len(buffer(arr))
  
  # In both cases below we need to make sure that the byte swapped value (as
  # UCS4) is still a valid unicode:
  # Value that can be represented in UCS2 interpreters
  ucs2_value = sixu('\u0900')
  # Value that cannot be represented in UCS2 interpreters (but can in UCS4)
  ucs4_value = sixu('\U00100900')
  
  
  def test_string_cast():
      str_arr = np.array(["1234", "1234\0\0"], dtype='S')
      uni_arr1 = str_arr.astype('>U')
      uni_arr2 = str_arr.astype('<U')
  
      if sys.version_info[0] < 3:
          assert_array_equal(str_arr, uni_arr1)
          assert_array_equal(str_arr, uni_arr2)
      else:
          assert_(str_arr != uni_arr1)
          assert_(str_arr != uni_arr2)
      assert_array_equal(uni_arr1, uni_arr2)
  
  
  ############################################################
  #    Creation tests
  ############################################################
  
  class create_zeros(object):
      """Check the creation of zero-valued arrays"""
  
      def content_check(self, ua, ua_scalar, nbytes):
  
          # Check the length of the unicode base type
          self.assertTrue(int(ua.dtype.str[2:]) == self.ulen)
          # Check the length of the data buffer
          self.assertTrue(buffer_length(ua) == nbytes)
          # Small check that data in array element is ok
          self.assertTrue(ua_scalar == sixu(''))
          # Encode to ascii and double check
          self.assertTrue(ua_scalar.encode('ascii') == asbytes(''))
          # Check buffer lengths for scalars
          if ucs4:
              self.assertTrue(buffer_length(ua_scalar) == 0)
          else:
              self.assertTrue(buffer_length(ua_scalar) == 0)
  
      def test_zeros0D(self):
          # Check creation of 0-dimensional objects
          ua = np.zeros((), dtype='U%s' % self.ulen)
          self.content_check(ua, ua[()], 4*self.ulen)
  
      def test_zerosSD(self):
          # Check creation of single-dimensional objects
          ua = np.zeros((2,), dtype='U%s' % self.ulen)
          self.content_check(ua, ua[0], 4*self.ulen*2)
          self.content_check(ua, ua[1], 4*self.ulen*2)
  
      def test_zerosMD(self):
          # Check creation of multi-dimensional objects
          ua = np.zeros((2, 3, 4), dtype='U%s' % self.ulen)
          self.content_check(ua, ua[0, 0, 0], 4*self.ulen*2*3*4)
          self.content_check(ua, ua[-1, -1, -1], 4*self.ulen*2*3*4)
  
  
  class test_create_zeros_1(create_zeros, TestCase):
      """Check the creation of zero-valued arrays (size 1)"""
      ulen = 1
  
  
  class test_create_zeros_2(create_zeros, TestCase):
      """Check the creation of zero-valued arrays (size 2)"""
      ulen = 2
  
  
  class test_create_zeros_1009(create_zeros, TestCase):
      """Check the creation of zero-valued arrays (size 1009)"""
      ulen = 1009
  
  
  class create_values(object):
      """Check the creation of unicode arrays with values"""
  
      def content_check(self, ua, ua_scalar, nbytes):
  
          # Check the length of the unicode base type
          self.assertTrue(int(ua.dtype.str[2:]) == self.ulen)
          # Check the length of the data buffer
          self.assertTrue(buffer_length(ua) == nbytes)
          # Small check that data in array element is ok
          self.assertTrue(ua_scalar == self.ucs_value*self.ulen)
          # Encode to UTF-8 and double check
          self.assertTrue(ua_scalar.encode('utf-8') ==
                          (self.ucs_value*self.ulen).encode('utf-8'))
          # Check buffer lengths for scalars
          if ucs4:
              self.assertTrue(buffer_length(ua_scalar) == 4*self.ulen)
          else:
              if self.ucs_value == ucs4_value:
                  # In UCS2, the \U0010FFFF will be represented using a
                  # surrogate *pair*
                  self.assertTrue(buffer_length(ua_scalar) == 2*2*self.ulen)
              else:
                  # In UCS2, the \uFFFF will be represented using a
                  # regular 2-byte word
                  self.assertTrue(buffer_length(ua_scalar) == 2*self.ulen)
  
      def test_values0D(self):
          # Check creation of 0-dimensional objects with values
          ua = np.array(self.ucs_value*self.ulen, dtype='U%s' % self.ulen)
          self.content_check(ua, ua[()], 4*self.ulen)
  
      def test_valuesSD(self):
          # Check creation of single-dimensional objects with values
          ua = np.array([self.ucs_value*self.ulen]*2, dtype='U%s' % self.ulen)
          self.content_check(ua, ua[0], 4*self.ulen*2)
          self.content_check(ua, ua[1], 4*self.ulen*2)
  
      def test_valuesMD(self):
          # Check creation of multi-dimensional objects with values
          ua = np.array([[[self.ucs_value*self.ulen]*2]*3]*4, dtype='U%s' % self.ulen)
          self.content_check(ua, ua[0, 0, 0], 4*self.ulen*2*3*4)
          self.content_check(ua, ua[-1, -1, -1], 4*self.ulen*2*3*4)
  
  
  class test_create_values_1_ucs2(create_values, TestCase):
      """Check the creation of valued arrays (size 1, UCS2 values)"""
      ulen = 1
      ucs_value = ucs2_value
  
  
  class test_create_values_1_ucs4(create_values, TestCase):
      """Check the creation of valued arrays (size 1, UCS4 values)"""
      ulen = 1
      ucs_value = ucs4_value
  
  
  class test_create_values_2_ucs2(create_values, TestCase):
      """Check the creation of valued arrays (size 2, UCS2 values)"""
      ulen = 2
      ucs_value = ucs2_value
  
  
  class test_create_values_2_ucs4(create_values, TestCase):
      """Check the creation of valued arrays (size 2, UCS4 values)"""
      ulen = 2
      ucs_value = ucs4_value
  
  
  class test_create_values_1009_ucs2(create_values, TestCase):
      """Check the creation of valued arrays (size 1009, UCS2 values)"""
      ulen = 1009
      ucs_value = ucs2_value
  
  
  class test_create_values_1009_ucs4(create_values, TestCase):
      """Check the creation of valued arrays (size 1009, UCS4 values)"""
      ulen = 1009
      ucs_value = ucs4_value
  
  
  ############################################################
  #    Assignment tests
  ############################################################
  
  class assign_values(object):
      """Check the assignment of unicode arrays with values"""
  
      def content_check(self, ua, ua_scalar, nbytes):
  
          # Check the length of the unicode base type
          self.assertTrue(int(ua.dtype.str[2:]) == self.ulen)
          # Check the length of the data buffer
          self.assertTrue(buffer_length(ua) == nbytes)
          # Small check that data in array element is ok
          self.assertTrue(ua_scalar == self.ucs_value*self.ulen)
          # Encode to UTF-8 and double check
          self.assertTrue(ua_scalar.encode('utf-8') ==
                          (self.ucs_value*self.ulen).encode('utf-8'))
          # Check buffer lengths for scalars
          if ucs4:
              self.assertTrue(buffer_length(ua_scalar) == 4*self.ulen)
          else:
              if self.ucs_value == ucs4_value:
                  # In UCS2, the \U0010FFFF will be represented using a
                  # surrogate *pair*
                  self.assertTrue(buffer_length(ua_scalar) == 2*2*self.ulen)
              else:
                  # In UCS2, the \uFFFF will be represented using a
                  # regular 2-byte word
                  self.assertTrue(buffer_length(ua_scalar) == 2*self.ulen)
  
      def test_values0D(self):
          # Check assignment of 0-dimensional objects with values
          ua = np.zeros((), dtype='U%s' % self.ulen)
          ua[()] = self.ucs_value*self.ulen
          self.content_check(ua, ua[()], 4*self.ulen)
  
      def test_valuesSD(self):
          # Check assignment of single-dimensional objects with values
          ua = np.zeros((2,), dtype='U%s' % self.ulen)
          ua[0] = self.ucs_value*self.ulen
          self.content_check(ua, ua[0], 4*self.ulen*2)
          ua[1] = self.ucs_value*self.ulen
          self.content_check(ua, ua[1], 4*self.ulen*2)
  
      def test_valuesMD(self):
          # Check assignment of multi-dimensional objects with values
          ua = np.zeros((2, 3, 4), dtype='U%s' % self.ulen)
          ua[0, 0, 0] = self.ucs_value*self.ulen
          self.content_check(ua, ua[0, 0, 0], 4*self.ulen*2*3*4)
          ua[-1, -1, -1] = self.ucs_value*self.ulen
          self.content_check(ua, ua[-1, -1, -1], 4*self.ulen*2*3*4)
  
  
  class test_assign_values_1_ucs2(assign_values, TestCase):
      """Check the assignment of valued arrays (size 1, UCS2 values)"""
      ulen = 1
      ucs_value = ucs2_value
  
  
  class test_assign_values_1_ucs4(assign_values, TestCase):
      """Check the assignment of valued arrays (size 1, UCS4 values)"""
      ulen = 1
      ucs_value = ucs4_value
  
  
  class test_assign_values_2_ucs2(assign_values, TestCase):
      """Check the assignment of valued arrays (size 2, UCS2 values)"""
      ulen = 2
      ucs_value = ucs2_value
  
  
  class test_assign_values_2_ucs4(assign_values, TestCase):
      """Check the assignment of valued arrays (size 2, UCS4 values)"""
      ulen = 2
      ucs_value = ucs4_value
  
  
  class test_assign_values_1009_ucs2(assign_values, TestCase):
      """Check the assignment of valued arrays (size 1009, UCS2 values)"""
      ulen = 1009
      ucs_value = ucs2_value
  
  
  class test_assign_values_1009_ucs4(assign_values, TestCase):
      """Check the assignment of valued arrays (size 1009, UCS4 values)"""
      ulen = 1009
      ucs_value = ucs4_value
  
  
  ############################################################
  #    Byteorder tests
  ############################################################
  
  class byteorder_values:
      """Check the byteorder of unicode arrays in round-trip conversions"""
  
      def test_values0D(self):
          # Check byteorder of 0-dimensional objects
          ua = np.array(self.ucs_value*self.ulen, dtype='U%s' % self.ulen)
          ua2 = ua.newbyteorder()
          # This changes the interpretation of the data region (but not the
          #  actual data), therefore the returned scalars are not
          #  the same (they are byte-swapped versions of each other).
          self.assertTrue(ua[()] != ua2[()])
          ua3 = ua2.newbyteorder()
          # Arrays must be equal after the round-trip
          assert_equal(ua, ua3)
  
      def test_valuesSD(self):
          # Check byteorder of single-dimensional objects
          ua = np.array([self.ucs_value*self.ulen]*2, dtype='U%s' % self.ulen)
          ua2 = ua.newbyteorder()
          self.assertTrue((ua != ua2).all())
          self.assertTrue(ua[-1] != ua2[-1])
          ua3 = ua2.newbyteorder()
          # Arrays must be equal after the round-trip
          assert_equal(ua, ua3)
  
      def test_valuesMD(self):
          # Check byteorder of multi-dimensional objects
          ua = np.array([[[self.ucs_value*self.ulen]*2]*3]*4,
                        dtype='U%s' % self.ulen)
          ua2 = ua.newbyteorder()
          self.assertTrue((ua != ua2).all())
          self.assertTrue(ua[-1, -1, -1] != ua2[-1, -1, -1])
          ua3 = ua2.newbyteorder()
          # Arrays must be equal after the round-trip
          assert_equal(ua, ua3)
  
      def test_values_cast(self):
          # Check byteorder of when casting the array for a strided and
          # contiguous array:
          test1 = np.array([self.ucs_value*self.ulen]*2, dtype='U%s' % self.ulen)
          test2 = np.repeat(test1, 2)[::2]
          for ua in (test1, test2):
              ua2 = ua.astype(dtype=ua.dtype.newbyteorder())
              self.assertTrue((ua == ua2).all())
              self.assertTrue(ua[-1] == ua2[-1])
              ua3 = ua2.astype(dtype=ua.dtype)
              # Arrays must be equal after the round-trip
              assert_equal(ua, ua3)
  
      def test_values_updowncast(self):
          # Check byteorder of when casting the array to a longer and shorter
          # string length for strided and contiguous arrays
          test1 = np.array([self.ucs_value*self.ulen]*2, dtype='U%s' % self.ulen)
          test2 = np.repeat(test1, 2)[::2]
          for ua in (test1, test2):
              # Cast to a longer type with zero padding
              longer_type = np.dtype('U%s' % (self.ulen+1)).newbyteorder()
              ua2 = ua.astype(dtype=longer_type)
              self.assertTrue((ua == ua2).all())
              self.assertTrue(ua[-1] == ua2[-1])
              # Cast back again with truncating:
              ua3 = ua2.astype(dtype=ua.dtype)
              # Arrays must be equal after the round-trip
              assert_equal(ua, ua3)
  
  
  class test_byteorder_1_ucs2(byteorder_values, TestCase):
      """Check the byteorder in unicode (size 1, UCS2 values)"""
      ulen = 1
      ucs_value = ucs2_value
  
  
  class test_byteorder_1_ucs4(byteorder_values, TestCase):
      """Check the byteorder in unicode (size 1, UCS4 values)"""
      ulen = 1
      ucs_value = ucs4_value
  
  
  class test_byteorder_2_ucs2(byteorder_values, TestCase):
      """Check the byteorder in unicode (size 2, UCS2 values)"""
      ulen = 2
      ucs_value = ucs2_value
  
  
  class test_byteorder_2_ucs4(byteorder_values, TestCase):
      """Check the byteorder in unicode (size 2, UCS4 values)"""
      ulen = 2
      ucs_value = ucs4_value
  
  
  class test_byteorder_1009_ucs2(byteorder_values, TestCase):
      """Check the byteorder in unicode (size 1009, UCS2 values)"""
      ulen = 1009
      ucs_value = ucs2_value
  
  
  class test_byteorder_1009_ucs4(byteorder_values, TestCase):
      """Check the byteorder in unicode (size 1009, UCS4 values)"""
      ulen = 1009
      ucs_value = ucs4_value
  
  
  if __name__ == "__main__":
      run_module_suite()
  