Trac #33691: some care for pep8 in pyx in modular

found using
{{{
pycodestyle --select
E111,E401,E701,E702,E703,W605,E711,E712,E713,E721,E722 --filename=*.pyx
src/sage/modular/
}}}

URL: https://trac.sagemath.org/33691
Reported by: chapoton
Ticket author(s): Frédéric Chapoton
Reviewer(s): David Coudert

src/sage/modular/arithgroup/arithgroup_element.pyx

@@ -194,7 +194,7 @@ cdef class ArithmeticSubgroupElement(MultiplicativeGroupElement):
         return richcmp(self.__x, right.__x, op)
 
     def __bool__(self):
-        """
+        r"""
         Return ``True``, since the ``self`` lives in SL(2,\Z), which does not
         contain the zero matrix.
 

src/sage/modular/arithgroup/congroup.pyx

@@ -1,18 +1,18 @@
-"""
+r"""
 Cython helper functions for congruence subgroups
 
 This file contains optimized Cython implementations of a few functions related
 to the standard congruence subgroups `\Gamma_0, \Gamma_1, \Gamma_H`.  These
 functions are for internal use by routines elsewhere in the Sage library.
 """
 
-#*****************************************************************************
+# ****************************************************************************
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
-#*****************************************************************************
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
 
 from cysignals.memory cimport check_allocarray, sig_free
 
@@ -28,7 +28,7 @@ from sage.matrix.matrix_integer_dense cimport Matrix_integer_dense
 from sage.modular.modsym.p1list import lift_to_sl2z
 from sage.matrix.matrix_space import MatrixSpace
 from sage.rings.integer_ring import ZZ
-Mat2Z = MatrixSpace(ZZ,2)
+Mat2Z = MatrixSpace(ZZ, 2)
 
 cdef Matrix_integer_dense genS, genT, genI
 genS = Matrix_integer_dense(Mat2Z, [0,-1, 1, 0], True, True)
@@ -124,9 +124,11 @@ def degeneracy_coset_representatives_gamma0(int N, int M, int t):
         cc = M*random.randrange(-halfmax, halfmax+1)
         dd =   random.randrange(-halfmax, halfmax+1)
         g = arith_int.c_xgcd_int(-cc,dd,&bb,&aa)
-        if g == 0: continue
+        if g == 0:
+            continue
         cc = cc / g
-        if cc % M != 0: continue
+        if cc % M != 0:
+            continue
         dd = dd / g
         # Test if we've found a new coset representative.
         is_new = 1
@@ -212,7 +214,6 @@ def degeneracy_coset_representatives_gamma1(int N, int M, int t):
     cdef int d, g, i, j, k, n, aa, bb, cc, dd, Ndivt, halfmax, is_new
     cdef int* R
 
-
     # total number of coset representatives that we'll find
     n = Gamma1(N).index() / Gamma1(M).index()
     d = arith_int.c_gcd_int(t, N/t)
@@ -226,11 +227,14 @@ def degeneracy_coset_representatives_gamma1(int N, int M, int t):
         cc =     M*random.randrange(-halfmax, halfmax+1)
         dd = 1 + M*random.randrange(-halfmax, halfmax+1)
         g = arith_int.c_xgcd_int(-cc,dd,&bb,&aa)
-        if g == 0: continue
+        if g == 0:
+            continue
         cc = cc / g
-        if cc % M != 0: continue
+        if cc % M != 0:
+            continue
         dd = dd / g
-        if M != 1 and dd % M != 1: continue
+        if M != 1 and dd % M != 1:
+            continue
         # Test if we've found a new coset representative.
         is_new = 1
         for i from 0 <= i < k:

src/sage/modular/arithgroup/farey_symbol.pyx

@@ -610,7 +610,7 @@ cdef class Farey:
         if forced_format == 'plain':
             # output not using xymatrix
             s = r'\left( -\infty'
-            a = [x._latex_() for x in self.fractions()] + ['\infty']
+            a = [x._latex_() for x in self.fractions()] + [r'\infty']
             b = self.pairings()
             for i in xrange(len(a)):
                 u = b[i]
@@ -623,7 +623,7 @@ cdef class Farey:
         else:
             # output using xymatrix
             s = r'\begin{xy}\xymatrix{& -\infty '
-            f = [x._latex_() for x in self.fractions()]+[r'\infty']
+            f = [x._latex_() for x in self.fractions()] + [r'\infty']
             f.reverse()
             for p in self.pairings():
                 if p >= 0:

src/sage/modular/modsym/heilbronn.pyx

@@ -211,7 +211,7 @@ cdef class Heilbronn:
         sig_off()
 
     cdef apply_to_polypart(self, fmpz_poly_t* ans, int i, int k):
-        """
+        r"""
         INPUT:
 
         -  ``ans`` - fmpz_poly_t\*; pre-allocated an
@@ -402,7 +402,11 @@ cdef class HeilbronnCremona(Heilbronn):
                 a = -b
                 b = c
                 x3 = q*x2 - x1
-                x1 = x2; x2 = x3; y3 = q*y2 - y1; y1 = y2; y2 = y3
+                x1 = x2
+                x2 = x3
+                y3 = q*y2 - y1
+                y1 = y2
+                y2 = y3
                 list_append4(L, x1,x2, y1,y2)
         self.length = L.i/4
         sig_off()
@@ -573,9 +577,11 @@ def hecke_images_gamma0_weight2(int u, int v, int N, indices, R):
 
         # Allocate memory to hold images of (u,v) under all Heilbronn matrices
         a = <int*> sig_malloc(sizeof(int)*H.length)
-        if not a: raise MemoryError
+        if not a:
+            raise MemoryError
         b = <int*> sig_malloc(sizeof(int)*H.length)
-        if not b: raise MemoryError
+        if not b:
+            raise MemoryError
 
         # Compute images of (u,v) under all Heilbronn matrices
         H.apply_only(u, v, N, a, b)
@@ -708,9 +714,11 @@ def hecke_images_nonquad_character_weight2(int u, int v, int N, indices, chi, R)
 
         # Allocate memory to hold images of (u,v) under all Heilbronn matrices
         a = <int*> sig_malloc(sizeof(int)*H.length)
-        if not a: raise MemoryError
+        if not a:
+            raise MemoryError
         b = <int*> sig_malloc(sizeof(int)*H.length)
-        if not b: raise MemoryError
+        if not b:
+            raise MemoryError
 
         # Compute images of (u,v) under all Heilbronn matrices
         H.apply_only(u, v, N, a, b)
@@ -798,16 +806,19 @@ def hecke_images_quad_character_weight2(int u, int v, int N, indices, chi, R):
     # are the values of the character chi.
     _chivals = chi.values()
     cdef int *chi_vals = <int*>sig_malloc(sizeof(int)*len(_chivals))
-    if not chi_vals: raise MemoryError
+    if not chi_vals:
+        raise MemoryError
     for i in range(len(_chivals)):
         chi_vals[i] = _chivals[i]
 
     for i, n in enumerate(indices):
         H = HeilbronnCremona(n) if is_prime(n) else HeilbronnMerel(n)
         a = <int*> sig_malloc(sizeof(int)*H.length)
-        if not a: raise MemoryError
+        if not a:
+            raise MemoryError
         b = <int*> sig_malloc(sizeof(int)*H.length)
-        if not b: raise MemoryError
+        if not b:
+            raise MemoryError
 
         H.apply_only(u, v, N, a, b)
         for j in range(H.length):
@@ -893,9 +904,11 @@ def hecke_images_gamma0_weight_k(int u, int v, int i, int N, int k, indices, R):
 
         # Allocate memory to hold images of (u,v) under all Heilbronn matrices
         a = <int*> sig_malloc(sizeof(int)*H.length)
-        if not a: raise MemoryError
+        if not a:
+            raise MemoryError
         b = <int*> sig_malloc(sizeof(int)*H.length)
-        if not b: raise MemoryError
+        if not b:
+            raise MemoryError
 
         # Compute images of (u,v) under all Heilbronn matrices
         H.apply_only(u, v, N, a, b)

src/sage/modular/modsym/manin_symbol.pyx

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-"""
+r"""
 Manin symbols
 
 This module defines the class ManinSymbol.  A Manin symbol of
@@ -19,9 +19,7 @@ monomial Manin symbols to monomial Manin symbols, up to a scalar
 factor.  For general matrices (such as `T=[0,1,-1,-1]` and
 `T^2=[-1,-1;0,1]`) the image of a monomial Manin symbol is expressed
 as a formal sum of monomial Manin symbols, with integer coefficients.
-
 """
-
 from sage.modular.cusps import Cusp
 from sage.rings.all import Infinity, ZZ
 from sage.rings.integer cimport Integer