fix suggested details and a few more

Author: fchapoton

src/sage/coding/cyclic_code.py

@@ -577,16 +577,17 @@ def field_embedding(self):
               To:   Finite Field in z3 of size 2^3
               Defn: 1 |--> 1
         """
-        if not (hasattr(self, "_field_embedding")):
+        if not hasattr(self, "_field_embedding"):
             self.defining_set()
         return self._field_embedding
 
     def defining_set(self, primitive_root=None):
         r"""
         Return the set of exponents of the roots of ``self``'s generator
-        polynomial over the extension field. Of course, it depends on the
-        choice of the primitive root of the splitting field.
+        polynomial over the extension field.
 
+        Of course, it depends on the choice of the primitive root of
+        the splitting field.
 
         INPUT:
 

src/sage/coding/grs_code.py

@@ -1229,14 +1229,15 @@ def _decode_to_code_and_message(self, r):
         col_mults = C.column_multipliers()
 
         r_list = copy(r)
-        r_list = [r[i]/col_mults[i] for i in range(0, C.length())]
-
-        t = (C.minimum_distance()-1) // 2
-        l0 = n-1-t
-        l1 = n-1-t-(k-1)
-        S = matrix(C.base_field(), n, l0+l1+2,
-                   lambda i, j: (C.evaluation_points()[i])**j if j < (l0+1)
-                   else r_list[i]*(C.evaluation_points()[i])**(j-(l0+1)))
+        r_list = [r[i] / col_mults[i] for i in range(C.length())]
+
+        t = (C.minimum_distance() - 1) // 2
+        l0 = n - 1 - t
+        l1 = n - t - k
+        pts = C.evaluation_points()
+        S = matrix(C.base_field(), n, l0 + l1 + 2,
+                   lambda i, j: (pts[i]**j if j < (l0 + 1)
+                                 else r_list[i] * pts[i]**(j - (l0 + 1))))
         S = S.right_kernel()
         S = S.basis_matrix().row(0)
         R = C.base_field()['x']
@@ -1574,7 +1575,7 @@ def _partial_xgcd(self, a, b, PolRing):
 
         r = b
         prev_r = a
-        while (r.degree() >= stop):
+        while r.degree() >= stop:
             q = prev_r.quo_rem(r)[0]
             (prev_r, r) = (r, prev_r - q * r)
             (prev_s, s) = (s, prev_s - q * s)
@@ -2165,7 +2166,7 @@ def _partial_xgcd(self, a, b, PolRing):
         prev_r = a
         r = b
 
-        while (r.degree() >= t.degree()):
+        while r.degree() >= t.degree():
             q = prev_r.quo_rem(r)[0]
             prev_r, r = r, prev_r - q * r
             prev_t, t = t, prev_t - q * t

src/sage/coding/linear_code.py

@@ -877,7 +877,7 @@ def chinen_polynomial(self):
             P = RT(C.zeta_polynomial())*T**(d - dperp)
             if is_even(n):
                 Pd = q**(k-n/2)*RT(Cd.zeta_polynomial())
-            if not (is_even(n)):
+            if not is_even(n):
                 Pd = s*q**(k-(n+1)/2)*RT(Cd.zeta_polynomial())
             CP = P+Pd
             f = CP/CP(1,s)
@@ -886,7 +886,7 @@ def chinen_polynomial(self):
             P = RT(C.zeta_polynomial())
             if is_even(n):
                 Pd = q**(k-n/2)*RT(Cd.zeta_polynomial())
-            if not (is_even(n)):
+            if not is_even(n):
                 Pd = s*q**(k-(n+1)/2)*RT(Cd.zeta_polynomial())
             CP = P+Pd
             f = CP/CP(1,s)
@@ -1666,7 +1666,7 @@ def permutation_automorphism_group(self, algorithm="partition"):
                     gens = Gp.GeneratorsOfGroup()
                     stop = 1                    # get ready to stop
                     for x in gens:              # if one of these gens is not an auto then don't stop
-                        if not (self.is_permutation_automorphism(Sn_sage(x))):
+                        if not self.is_permutation_automorphism(Sn_sage(x)):
                             stop = 0
                             break
             G = PermutationGroup(list(map(Sn_sage, gens)))
@@ -1877,7 +1877,7 @@ def weight_distribution(self, algorithm=None):
             from sage.coding.binary_code import weight_dist
             return weight_dist(self.generator_matrix())
         elif algorithm == "leon":
-            if not (F.order() in [2,3,5,7]):
+            if F.order() not in [2, 3, 5, 7]:
                 raise NotImplementedError("The algorithm 'leon' is only implemented for q = 2,3,5,7.")
             # The GAP command DirectoriesPackageLibrary tells the location of the latest
             # version of the Guava libraries, so gives us the location of the Guava binaries too.

src/sage/coding/linear_code_no_metric.py

@@ -891,12 +891,9 @@ def is_subcode(self, other):
             True
         """
         G = self.generator_matrix()
-        for r in G.rows():
-            if not (r in other):
-                return False
-        return True
+        return all(r in other for r in G.rows())
 
-    def is_permutation_automorphism(self,g):
+    def is_permutation_automorphism(self, g):
         r"""
         Return `1` if `g` is an element of `S_n` (`n` = length of ``self``) and
         if `g` is an automorphism of ``self``.

src/sage/coding/punctured_code.py

@@ -328,7 +328,7 @@ def structured_representation(self):
         C = self.original_code()
         pts = copy(self.punctured_positions())
         list_pts = list(pts)
-        while (isinstance(C, PuncturedCode)):
+        while isinstance(C, PuncturedCode):
             cur_pts = list(C.punctured_positions())
             list_len = len(list_pts)
             for p in cur_pts:

src/sage/coding/reed_muller_code.py

@@ -258,9 +258,9 @@ def __init__(self, base_field, order, num_of_var):
         # input sanitization
         if base_field not in FiniteFields():
             raise ValueError("the input `base_field` must be a FiniteField")
-        if not (isinstance(order, (Integer, int))):
+        if not isinstance(order, (Integer, int)):
             raise ValueError("The order of the code must be an integer")
-        if not (isinstance(num_of_var, (Integer, int))):
+        if not isinstance(num_of_var, (Integer, int)):
             raise ValueError("The number of variables must be an integer")
         q = base_field.cardinality()
         if order >= q:
@@ -425,9 +425,9 @@ def __init__(self, order, num_of_var):
             ValueError: The order of the code must be an integer
         """
         # input sanitization
-        if not (isinstance(order, (Integer, int))):
+        if not isinstance(order, (Integer, int)):
             raise ValueError("The order of the code must be an integer")
-        if not (isinstance(num_of_var, (Integer, int))):
+        if not isinstance(num_of_var, (Integer, int)):
             raise ValueError("The number of variables must be an integer")
         if (num_of_var < order):
             raise ValueError(