introduced name attribute

tfields/core.py

@@ -283,9 +283,9 @@ class AbstractNdarray(np.ndarray):
             >>> import tfields
             >>> from tempfile import NamedTemporaryFile
             >>> out_file = NamedTemporaryFile(suffix='.npz')
-            >>> p = tfields.Points3D([[1., 2., 3.], [4., 5., 6.], [1, 2, -6]])
-
-            >>> scalars = tfields.Tensors([0, 1, 2])
+            >>> p = tfields.Points3D([[1., 2., 3.], [4., 5., 6.], [1, 2, -6]],
+            ...                      name='my_points')
+            >>> scalars = tfields.Tensors([0, 1, 2], name=42)
             >>> vectors = tfields.Tensors([[0, 0, 0], [0, 0, 1], [0, -1, 0]])
             >>> maps = [tfields.TensorFields([[0, 1, 2], [0, 1, 2]], [42, 21]),
             ...         tfields.TensorFields([[1], [2]], [-42, -21])]
@@ -306,6 +306,11 @@ class AbstractNdarray(np.ndarray):
             >>> assert m.equal(m1)
             >>> assert m.maps[0].dtype == m1.maps[0].dtype
 
+            Names are preserved
+            >>> assert p.name == 'my_points'
+            >>> m.names
+            [42]
+
         """
         content_dict = self._as_dict()
         np.savez(path, **content_dict)
@@ -477,7 +482,7 @@ class Tensors(AbstractNdarray):
         Tensors([], shape=(0, 7), dtype=float64)
 
     """
-    __slots__ = ['coord_sys']
+    __slots__ = ['coord_sys', 'name']
     __slot_defaults__ = ['cartesian']
     __slot_setters__ = [tfields.bases.get_coord_system_name]
 
@@ -494,6 +499,7 @@ class Tensors(AbstractNdarray):
             tensors = tensors.copy()
             tensors.transform(coord_sys)
             kwargs['coord_sys'] = coord_sys
+            kwargs['name'] = kwargs.pop('name', tensors.name)
             if dtype is None:
                 dtype = tensors.dtype
         else:
@@ -1419,7 +1425,7 @@ class TensorFields(Tensors):
         >>> assert len(loose) != 1
 
     """
-    __slots__ = ['coord_sys', 'fields']
+    __slots__ = ['coord_sys', 'name', 'fields']
 
     def __new__(cls, tensors, *fields, **kwargs):
         rigid = kwargs.pop('rigid', True)
@@ -1442,6 +1448,7 @@ class TensorFields(Tensors):
                 raise ValueError("Length of base ({olen}) should be the same as"
                                  " the length of all fields ({field_lengths})."
                                  .format(**locals()))
+
         return obj
 
     def __getitem__(self, index):
@@ -1544,6 +1551,32 @@ class TensorFields(Tensors):
         inst = cls.__new__(cls, inst, *fields)
         return inst
 
+    @property
+    def names(self):
+        """
+        Retrive the names of the fields as a list
+
+        Examples:
+            >>> import numpy as np
+            >>> import tfields
+            >>> s = tfields.Tensors([1,2,3], name=1.)
+            >>> tf = tfields.TensorFields(s, *[s]*10)
+            >>> assert len(tf.names) == 10
+            >>> assert set(tf.names) == {1.}
+            >>> tf.names = range(10)
+            >>> tf.names
+            [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+
+        """
+        return [f.name for f in self.fields]
+
+    @names.setter
+    def names(self, names):
+        if not len(names) == len(self.fields):
+            raise ValueError("len(names) != len(fields)")
+        for i, name in enumerate(names):
+            self.fields[i].name = name
+
     # def transform(self, coord_sys):
     #     super(TensorFields, self).transform(coord_sys)
     #     # for field in self.fields:
@@ -1653,7 +1686,7 @@ class TensorMaps(TensorFields):
         ValueError: Incorrect map rank 0
 
     """
-    __slots__ = ['coord_sys', 'fields', 'maps']
+    __slots__ = ['coord_sys', 'name', 'fields', 'maps']
 
     def __new__(cls, tensors, *fields, **kwargs):
         maps = kwargs.pop('maps', [])