def test_instance_attribute():
iattr = InstanceAttribute('type_array', dim='atom', dtype='str')
eq_(iattr.size, 0)
# Now we initialize as empty
iattr.empty(10)
eq_(iattr.size, 10)
# We get another one
iattr = InstanceAttribute('type_array', dim='atom', dtype='str')
iattr.value = ['A', 'B', 'C', 'D']
# Automatic casting
ok_(isinstance(iattr.value, np.ndarray))
assert_npequal(iattr.value, ['A', 'B', 'C', 'D'])
# Reordering
iattr2 = iattr.reorder([1, 0, 3, 2], inplace=False)
assert_npequal(iattr2.value, ['B', 'A', 'D', 'C'])
iattr.reorder([1, 0, 3, 2])
assert_npequal(iattr.value, ['B', 'A', 'D', 'C'])
# Reordering with wrong input raises ValueError
assert_raises(ValueError, iattr.reorder, [1, 2])
assert_raises(ValueError, iattr.reorder, [0, 1, 2, 100])
# Test Copy
iattr = InstanceAttribute('type_array', dim='atom', dtype='str')
iattr.empty(3)
iattr.value = ['O', 'H', 'H']
iattr2 = iattr.copy()
assert_npequal(iattr2.value, iattr.value)
iattr2.value = ['A', 'B', 'C']
assert_npequal(iattr.value, ['O', 'H', 'H'])
assert_npequal(iattr2.value, ['A', 'B', 'C'])
iattr = InstanceAttribute('type_array', dim='atom', dtype='str')
iattr.empty(3)
iattr.value = ['O', 'H', 'H']
iattr1 = iattr.sub([0, 1])
assert_npequal(iattr1.value, ['O', 'H'])
iattr1 = iattr.sub([False, True, False])
assert_npequal(iattr1.value, ['H'])
