two more details in tableaux

Author: fchapoton

src/sage/combinat/ribbon_tableau.py

@@ -854,8 +854,8 @@ def weight(self):
             sage: a.weight()
             [5, 3, 1]
         """
-        weights = [x.weight() for x in self]
-        m = max([len(x) for x in weights])
+        weights = (x.weight() for x in self)
+        m = max(len(x) for x in weights)
         weight = [0] * m
         for w in weights:
             for i in range(len(w)):

src/sage/combinat/tableau.py

@@ -1298,7 +1298,7 @@ def to_sign_matrix(self, max_entry=None):
                 raise ValueError("the entries must be nonnegative integers")
         from sage.matrix.matrix_space import MatrixSpace
         if max_entry is None:
-            max_entry = max([max(c) for c in self])
+            max_entry = max(max(c) for c in self)
         MS = MatrixSpace(ZZ, len(self[0]), max_entry)
         Tconj = self.conjugate()
         conj_len = len(Tconj)