src/sage/tensor: Allow _sym, _antisym attributes to be tuples

src/sage/manifolds/differentiable/tensorfield.py

@@ -957,13 +957,13 @@ def symmetries(self):
         elif len(self._sym) == 1:
             s = "symmetry: {}; ".format(self._sym[0])
         else:
-            s = "symmetries: {}; ".format(self._sym)
+            s = "symmetries: {}; ".format(list(self._sym))
         if not self._antisym:
             a = "no antisymmetry"
         elif len(self._antisym) == 1:
             a = "antisymmetry: {}".format(self._antisym[0])
         else:
-            a = "antisymmetries: {}".format(self._antisym)
+            a = "antisymmetries: {}".format(list(self._antisym))
         print(s + a)
 
     #### End of simple accessors #####

src/sage/tensor/modules/comp.py

@@ -1773,12 +1773,12 @@ def __mul__(self, other):
                              "same starting index")
         if isinstance(other, CompWithSym):
             sym = []
-            if other._sym != []:
+            if other._sym:
                 for s in other._sym:
                     ns = tuple(s[i]+self._nid for i in range(len(s)))
                     sym.append(ns)
             antisym = []
-            if other._antisym != []:
+            if other._antisym:
                 for s in other._antisym:
                     ns = tuple(s[i]+self._nid for i in range(len(s)))
                     antisym.append(ns)
@@ -3011,7 +3011,12 @@ def _canonicalize_sym_antisym(nb_indices, sym=None, antisym=None):
             ([(2, 1)], [])
         """
         result_sym = []
-        if sym is not None and sym != []:
+        if sym is None:
+            sym = []
+        else:
+            # Handle the case that sym is an iterator
+            sym = list(sym)
+        if sym:
             if isinstance(sym[0], (int, Integer)):
                 # a single symmetry is provided as a tuple or a range object;
                 # it is converted to a 1-item list:
@@ -3026,7 +3031,12 @@ def _canonicalize_sym_antisym(nb_indices, sym=None, antisym=None):
                                          " not in [0," + str(nb_indices-1) + "]")
                 result_sym.append(tuple(isym))
         result_antisym = []
-        if antisym is not None and antisym != []:
+        if antisym is None:
+            antisym = []
+        else:
+            # Handle the case that antisym is an iterator
+            antisym = list(antisym)
+        if antisym:
             if isinstance(antisym[0], (int, Integer)):
                 # a single antisymmetry is provided as a tuple or a range
                 # object; it is converted to a 1-item list:
@@ -3535,7 +3545,7 @@ def paral_sum(a, b, local_list_ind):
                         com = tuple(set(isym).intersection(set(osym)))
                         if len(com) > 1:
                             common_antisym.append(com)
-                if common_sym != [] or common_antisym != []:
+                if common_sym or common_antisym:
                     result = CompWithSym(self._ring, self._frame, self._nid,
                                          self._sindex, self._output_formatter,
                                          common_sym, common_antisym)
@@ -3643,11 +3653,11 @@ def __mul__(self, other):
         sym = list(self._sym)
         antisym = list(self._antisym)
         if isinstance(other, CompWithSym):
-            if other._sym != []:
+            if other._sym:
                 for s in other._sym:
                     ns = tuple(s[i]+self._nid for i in range(len(s)))
                     sym.append(ns)
-            if other._antisym != []:
+            if other._antisym:
                 for s in other._antisym:
                     ns = tuple(s[i]+self._nid for i in range(len(s)))
                     antisym.append(ns)
@@ -3973,7 +3983,7 @@ def non_redundant_index_generator(self):
         si = self._sindex
         imax = self._dim - 1 + si
         ind = [si for k in range(self._nid)]
-        sym = self._sym.copy() # we may modify this in the following
+        sym = list(self._sym)  # we may modify this in the following
         antisym = self._antisym
         for pos in range(self._nid):
             for isym in antisym:

src/sage/tensor/modules/free_module_tensor.py

@@ -563,13 +563,13 @@ def symmetries(self):
         elif len(self._sym) == 1:
             s = "symmetry: {}; ".format(self._sym[0])
         else:
-            s = "symmetries: {}; ".format(self._sym)
+            s = "symmetries: {}; ".format(list(self._sym))
         if len(self._antisym) == 0:
             a = "no antisymmetry"
         elif len(self._antisym) == 1:
             a = "antisymmetry: {}".format(self._antisym[0])
         else:
-            a = "antisymmetries: {}".format(self._antisym)
+            a = "antisymmetries: {}".format(list(self._antisym))
         print(s+a)
 
     #### End of simple accessors #####