Trac #33889: get rid of some range(0,*) in pyx files

We replace some `range(0, a)` by `range(a)`,
occasionally replacing `xrange` by `range`
or a list by an iterator.

URL: https://trac.sagemath.org/33889
Reported by: chapoton
Ticket author(s): Frédéric Chapoton
Reviewer(s): Samuel Lelièvre

Author: Release Manager

src/sage/coding/binary_code.pyx

@@ -3927,7 +3927,7 @@ cdef class BinaryCodeClassifier:
 
             sage: soc_iter = codes.databases.self_orthogonal_binary_codes(12, 6, 4)
             sage: L = list(soc_iter)
-            sage: for n in range(0, 13):
+            sage: for n in range(13):
             ....:   s = 'n=%2d : '%n
             ....:   for k in range(1,7):
             ....:       s += '%3d '%len([C for C in L if C.length() == n and C.dimension() == k])

src/sage/geometry/integral_points.pyx

@@ -49,12 +49,12 @@ from sage.matrix.matrix_integer_dense cimport Matrix_integer_dense
 ##     # R*Rinv == diagonal_matrix([d]*D.ncols() + [0]*(D.nrows()-D.ncols()))
 ##     # If R is full rank, this is Rinv = matrix(ZZ, R.inverse() * d)
 ##     Dinv = D.transpose()
-##     for i in range(0,D.ncols()):
+##     for i in range(D.ncols()):
 ##         Dinv[i,i] = d/D[i,i]
 ##     Rinv = V * Dinv * U
 ##
 ##     gens = []
-##     for b in CartesianProduct(*[ range(0,i) for i in e ]):
+##     for b in CartesianProduct(*[ range(i) for i in e ]):
 ##         # this is our generator modulo the lattice spanned by the rays
 ##         gen_mod_rays = sum( b_i*u_i for b_i, u_i in zip(b,u) )
 ##         q_times_d = Rinv * gen_mod_rays
@@ -175,7 +175,7 @@ cpdef tuple ray_matrix_normal_form(R):
     if d == ZZ.zero():
         raise ValueError('The spanning points are not linearly independent!')
     cdef int i
-    Dinv = diagonal_matrix(ZZ, [ d // e[i] for i in range(0,D.ncols()) ])
+    Dinv = diagonal_matrix(ZZ, [ d // e[i] for i in range(D.ncols()) ])
     VDinv = V * Dinv
     return (e, d, VDinv)
 
@@ -224,20 +224,20 @@ cpdef tuple loop_over_parallelotope_points(e, d, Matrix_integer_dense VDinv,
     cdef list gens = []
     gen = lattice(ZZ.zero())
     cdef Vector_integer_dense q_times_d = vector(ZZ, dim)
-    for base in itertools.product(*[ range(0,i) for i in e ]):
-        for i in range(0, dim):
+    for base in itertools.product(*[ range(i) for i in e ]):
+        for i in range(dim):
             s = ZZ.zero()
-            for j in range(0, dim):
+            for j in range(dim):
                 s += VDinv.get_unsafe(i,j) * base[j]
             q_times_d.set_unsafe(i, s % d)
-        for i in range(0, ambient_dim):
+        for i in range(ambient_dim):
             s = ZZ.zero()
-            for j in range(0, dim):
+            for j in range(dim):
                 s += R.get_unsafe(i,j) * q_times_d.get_unsafe(j)
             gen[i] = s / d
         if A is not None:
             s = ZZ.zero()
-            for i in range(0, ambient_dim):
+            for i in range(ambient_dim):
                 s += A[i] * gen[i]
             if s > b:
                 continue
@@ -341,7 +341,7 @@ cdef translate_points(v_list, Vector_integer_dense delta):
     cdef int dim = delta.degree()
     cdef int i
     for v in v_list:
-        for i in range(0,dim):
+        for i in range(dim):
             v[i] -= delta.get_unsafe(i)
 
 
@@ -549,7 +549,7 @@ cpdef rectangular_box_points(list box_min, list box_max,
     assert not (count_only and return_saturated)
     cdef int d = len(box_min)
     cdef int i, j
-    cdef list diameter = sorted([ (box_max[i]-box_min[i], i) for i in range(0,d) ],
+    cdef list diameter = sorted([ (box_max[i]-box_min[i], i) for i in range(d) ],
                                 reverse=True)
     cdef list diameter_value = [x[0] for x in diameter]
     cdef list diameter_index = [x[1] for x in diameter]
@@ -790,7 +790,7 @@ cdef class Inequality_generic:
             'generic: (2, 3, 7) x + -5 >= 0'
         """
         s = 'generic: ('
-        s += ', '.join([str(self.A[i]) for i in range(0,len(self.A))])
+        s += ', '.join(str(self.A[i]) for i in range(len(self.A)))
         s += ') x + ' + str(self.b) + ' >= 0'
         return s
 

src/sage/libs/mpmath/ext_impl.pyx

@@ -2036,7 +2036,7 @@ cdef MPF_hypsum(MPF *a, MPF *b, int p, int q, param_types, str ztype, coeffs, z,
         mpz_set_complex_tuple_fixed(ZRE, ZIM, z, wp)
     else:
         mpz_set_tuple_fixed(ZRE, z, wp)
-    for i in range(0,p):
+    for i in range(p):
         sig_check()
         if param_types[i] == 'Z':
             mpz_init(AINT[aint])

src/sage/matroids/matroid.pyx

@@ -2351,7 +2351,7 @@ cdef class Matroid(SageObject):
             False
         """
         E = list(self.groundset())
-        for i in xrange(0, len(E) + 1):
+        for i in range(len(E) + 1):
             for X in combinations(E, i):
                 XX = frozenset(X)
                 rX = self._rank(XX)

src/sage/rings/polynomial/real_roots.pyx

@@ -2109,14 +2109,14 @@ def bernstein_up(d1, d2, s=None):
     MS = MatrixSpace(QQ, s, d1+1, sparse=False)
     m = MS()
     scale = factorial(d2)/factorial(d2-d1)
-    for b in range(0, d1+1):
+    for b in range(d1 + 1):
         scale2 = scale / binomial(d1, b)
         if (d1 - b) & 1 == 1:
             scale2 = -scale2
         scale2 = ~scale2
-        for a in range(0, s):
+        for a in range(s):
             ra = ZZ(subsample_vec(a, s, d2 + 1))
-            m[a, b] = prod([ra-i for i in range(0, b)]) * prod([ra-i for i in range(d2-d1+b+1, d2+1)]) * scale2
+            m[a, b] = prod([ra-i for i in range(b)]) * prod([ra-i for i in range(d2-d1+b+1, d2+1)]) * scale2
 
     return m
 
@@ -4369,7 +4369,7 @@ def to_bernstein(p, low=0, high=1, degree=None):
         raise ValueError('Bernstein degree must be at least polynomial degree')
     vs = ZZ ** (degree + 1)
     c = vs(0)
-    for i in range(0, p.degree() + 1):
+    for i in range(p.degree() + 1):
         c[i] = p[i]
     scale = ZZ(1)
     if low == 0:
@@ -4385,7 +4385,8 @@ def to_bernstein(p, low=0, high=1, degree=None):
     reverse_intvec(c)
     taylor_shift1_intvec(c)
     reverse_intvec(c)
-    return ([c[k] / binomial(degree, k) for k in range(0, degree+1)], scale)
+    return ([c[k] / binomial(degree, k) for k in range(degree + 1)], scale)
+
 
 def to_bernstein_warp(p):
     """
@@ -4399,14 +4400,12 @@ def to_bernstein_warp(p):
         sage: to_bernstein_warp(1 + x + x^2 + x^3 + x^4 + x^5)
         [1, 1/5, 1/10, 1/10, 1/5, 1]
     """
-
     c = p.list()
-
     for i in range(len(c)):
         c[i] = c[i] / binomial(len(c) - 1, i)
-
     return c
 
+
 def bernstein_expand(Vector_integer_dense c, int d2):
     """
     Given an integer vector representing a Bernstein polynomial p, and

src/sage/sets/recursively_enumerated_set.pyx

@@ -273,7 +273,7 @@ convention is that the generated elements are the ``s := f(n)``, except when
     ....:     st = set(st) # make a copy
     ....:     if st:
     ....:        el = st.pop()
-    ....:        for i in range(0, len(lst)+1):
+    ....:        for i in range(len(lst)+1):
     ....:            yield (lst[0:i]+[el]+lst[i:], st)
     sage: list(children(([1,2], {3,7,9})))
     [([9, 1, 2], {3, 7}), ([1, 9, 2], {3, 7}), ([1, 2, 9], {3, 7})]

src/sage/structure/element.pyx

@@ -823,8 +823,8 @@ cdef class Element(SageObject):
         variables=[]
         # use "gen" instead of "gens" as a ParentWithGens is not
         # required to have the latter
-        for i in xrange(0,ngens):
-            gen=parent.gen(i)
+        for i in range(ngens):
+            gen = parent.gen(i)
             if str(gen) in kwds:
                 variables.append(kwds[str(gen)])
             elif in_dict and gen in in_dict: