Trac #34921: fix E714 in pyx files inside matrix/

about using "is not"

following #34895

URL: https://trac.sagemath.org/34921
Reported by: chapoton
Ticket author(s): Frédéric Chapoton
Reviewer(s): Martin Rubey

Author: Release Manager

src/sage/matrix/matrix0.pyx

@@ -204,7 +204,7 @@ cdef class Matrix(sage.structure.element.Matrix):
         cdef Py_ssize_t i, j
 
         x = self.fetch('list')
-        if not x is None:
+        if x is not None:
             return x
         x = []
         for i from 0 <= i < self._nrows:
@@ -309,7 +309,7 @@ cdef class Matrix(sage.structure.element.Matrix):
             [   3    4   10]
         """
         d = self.fetch('dict')
-        if not d is None:
+        if d is not None:
             return d
 
         cdef Py_ssize_t i, j
@@ -4612,7 +4612,8 @@ cdef class Matrix(sage.structure.element.Matrix):
             (0, 1)
         """
         x = self.fetch('pivots')
-        if not x is None: return tuple(x)
+        if x is not None:
+            return tuple(x)
         self.echelon_form()
         x = self.fetch('pivots')
         if x is None:
@@ -4650,10 +4651,10 @@ cdef class Matrix(sage.structure.element.Matrix):
             ....:                 [8*x^2 + 12*x + 15,  8*x^2 + 9*x + 16] ])
             sage: m.rank()
             2
-
         """
         x = self.fetch('rank')
-        if not x is None: return x
+        if x is not None:
+            return x
         if self._nrows == 0 or self._ncols == 0:
             return 0
         r = len(self.pivots())
@@ -4681,12 +4682,13 @@ cdef class Matrix(sage.structure.element.Matrix):
             (2,)
         """
         x = self.fetch('nonpivots')
-        if not x is None: return tuple(x)
+        if x is not None:
+            return tuple(x)
 
         X = set(self.pivots())
         np = []
         for j in xrange(self.ncols()):
-            if not (j in X):
+            if j not in X:
                 np.append(j)
         np = tuple(np)
         self.cache('nonpivots',np)
@@ -4777,7 +4779,7 @@ cdef class Matrix(sage.structure.element.Matrix):
             [(0, 0), (1, 0), (1, 1), (0, 2)]
         """
         x = self.fetch('nonzero_positions_by_column')
-        if not x is None:
+        if x is not None:
             if copy:
                 return list(x)
             return x

src/sage/matrix/matrix2.pyx

@@ -2798,7 +2798,7 @@ cdef class Matrix(Matrix1):
             (y + 1) * (y + 2)^2
         """
         f = self.fetch('minpoly')
-        if not f is None:
+        if f is not None:
             return f.change_variable_name(var)
         f = self.charpoly(var=var, **kwds)
         try:
@@ -3418,7 +3418,7 @@ cdef class Matrix(Matrix1):
             TypeError: Hessenbergize only possible for matrices over a field
         """
         X = self.fetch('hessenberg_form')
-        if not X is None:
+        if X is not None:
             return X
         R = self._base_ring
         if R not in _Fields:
@@ -4440,7 +4440,7 @@ cdef class Matrix(Matrix1):
 
         # Determine proof keyword for integer matrices
         proof = kwds.pop('proof', None)
-        if not (proof in [None, True, False]):
+        if proof not in [None, True, False]:
             raise ValueError("'proof' must be one of True, False or None, not %s" % proof)
         if not (proof is None or is_IntegerRing(R)):
             raise ValueError("'proof' flag only valid for matrices over the integers")
@@ -4851,7 +4851,7 @@ cdef class Matrix(Matrix1):
             True
         """
         K = self.fetch('right_kernel')
-        if not K is None:
+        if K is not None:
             verbose("retrieving cached right kernel for %sx%s matrix" % (self.nrows(), self.ncols()),level=1)
             return K
 
@@ -5027,7 +5027,7 @@ cdef class Matrix(Matrix1):
             True
         """
         K = self.fetch('left_kernel')
-        if not K is None:
+        if K is not None:
             verbose("retrieving cached left kernel for %sx%s matrix" % (self.nrows(), self.ncols()),level=1)
             return K
 
@@ -5124,7 +5124,7 @@ cdef class Matrix(Matrix1):
             True
         """
         A = self.restrict(V, check=check)
-        if not poly is None:
+        if poly is not None:
             A = poly(A)
         W = A.kernel()
         if V.is_ambient():
@@ -6266,7 +6266,7 @@ cdef class Matrix(Matrix1):
 
         key = 'eigenspaces_left_' + format + '{0}'.format(var)
         x = self.fetch(key)
-        if not x is None:
+        if x is not None:
             if algebraic_multiplicity:
                 return x
             else:
@@ -6508,7 +6508,7 @@ cdef class Matrix(Matrix1):
 
         key = 'eigenspaces_right_' + format + '{0}'.format(var)
         x = self.fetch(key)
-        if not x is None:
+        if x is not None:
             if algebraic_multiplicity:
                 return x
             else:
@@ -6746,7 +6746,7 @@ cdef class Matrix(Matrix1):
                                           % self.base_ring())
 
         x = self.fetch('eigenvectors_left')
-        if not x is None:
+        if x is not None:
             return x
 
         if not self.base_ring().is_exact():
@@ -7805,7 +7805,7 @@ cdef class Matrix(Matrix1):
             [0.000  1.00  1.00]
         """
         E = self.fetch('echelon_' + algorithm)
-        if not E is None:
+        if E is not None:
             return E
         E = self.__copy__()
         E._echelon_in_place(algorithm)
@@ -8591,7 +8591,7 @@ cdef class Matrix(Matrix1):
         """
         if self._ncols != right._nrows:
             raise ArithmeticError("Number of columns of self must equal number of rows of right.")
-        if not self._base_ring is right.base_ring():
+        if self._base_ring is not right.base_ring():
             raise TypeError("Base rings must be the same.")
 
         if cutoff == 0:
@@ -9643,7 +9643,7 @@ cdef class Matrix(Matrix1):
         """
         key = 'normal'
         n = self.fetch(key)
-        if not n is None:
+        if n is not None:
             return n
         if not self.is_square():
             self.cache(key, False)
@@ -9951,12 +9951,11 @@ cdef class Matrix(Matrix1):
 
         The result is cached.
         """
-
         if self._nrows != self._ncols:
             raise ValueError("must be a square matrix")
 
         X = self.fetch('adjugate')
-        if not X is None:
+        if X is not None:
             return X
 
         X = self._adjugate()
@@ -12402,7 +12401,7 @@ cdef class Matrix(Matrix1):
 
         iterates, poly, augmented, pivots = self._cyclic_subspace(v)
         k = len(pivots)
-        polynomial = not var is None
+        polynomial = (var is not None)
         if polynomial:
             x = sage.rings.polynomial.polynomial_ring.polygen(R, var)
             poly = sum([poly[i] * x**i for i in range(len(poly))])

src/sage/matrix/matrix_double_dense.pyx

@@ -1031,7 +1031,7 @@ cdef class Matrix_double_dense(Matrix_numpy_dense):
             return P, L, U
 
         PLU = self.fetch('PLU_factors')
-        if not PLU is None:
+        if PLU is not None:
             return PLU
         if scipy is None:
             import scipy
@@ -2351,7 +2351,7 @@ cdef class Matrix_double_dense(Matrix_numpy_dense):
             raise ValueError("algorithm must be 'naive' or 'orthonormal', not {0}".format(algorithm))
         key = 'unitary_{0}_{1}'.format(algorithm, tol)
         b = self.fetch(key)
-        if not b is None:
+        if b is not None:
             return b
         if not self.is_square():
             self.cache(key, False)
@@ -2479,7 +2479,7 @@ cdef class Matrix_double_dense(Matrix_numpy_dense):
 
         key = ("_is_hermitian_orthonormal", tol, skew)
         h = self.fetch(key)
-        if not h is None:
+        if h is not None:
             return h
         if not self.is_square():
             self.cache(key, False)
@@ -2910,7 +2910,7 @@ cdef class Matrix_double_dense(Matrix_numpy_dense):
 
         key = 'normal_{0}_{1}'.format(algorithm, tol)
         b = self.fetch(key)
-        if not b is None:
+        if b is not None:
             return b
         if not self.is_square():
             self.cache(key, False)
@@ -3214,7 +3214,7 @@ cdef class Matrix_double_dense(Matrix_numpy_dense):
             format = 'real'
 
         schur = self.fetch('schur_factors_' + format)
-        if not schur is None:
+        if schur is not None:
             return schur
         if scipy is None:
             import scipy

src/sage/matrix/matrix_gf2e_dense.pyx

@@ -903,7 +903,8 @@ cdef class Matrix_gf2e_dense(matrix_dense.Matrix_dense):
         full = int(reduced)
 
         x = self.fetch('in_echelon_form')
-        if not x is None: return  # already known to be in echelon form
+        if x is not None:
+            return  # already known to be in echelon form
 
         self.check_mutability()
         self.clear_cache()
@@ -1335,7 +1336,7 @@ cdef class Matrix_gf2e_dense(matrix_dense.Matrix_dense):
             0
         """
         x = self.fetch('rank')
-        if not x is None:
+        if x is not None:
             return x
         if self._nrows == 0 or self._ncols == 0:
             return 0
@@ -1517,6 +1518,7 @@ cdef class Matrix_gf2e_dense(matrix_dense.Matrix_dense):
         mzed_cling(self._entries, v)
         mzd_slice_free(v)
 
+
 def unpickle_matrix_gf2e_dense_v0(Matrix_mod2_dense a, base_ring, nrows, ncols):
     r"""
     EXAMPLES::

src/sage/matrix/matrix_integer_dense.pyx

@@ -2269,7 +2269,7 @@ cdef class Matrix_integer_dense(Matrix_dense):
             [ 0  0  0]
         """
         p = self.fetch('pivots')
-        if not p is None:
+        if p is not None:
             return tuple(p)
 
         cdef Matrix_integer_dense E
@@ -3582,7 +3582,7 @@ cdef class Matrix_integer_dense(Matrix_dense):
                              "or 'linbox'")
 
         r = self.fetch('rank')
-        if not r is None:
+        if r is not None:
             return r
 
         if algorithm == 'flint' or (self._nrows <= 6 and self._ncols <= 6

src/sage/matrix/matrix_integer_sparse.pyx

@@ -219,7 +219,7 @@ cdef class Matrix_integer_sparse(Matrix_sparse):
         be dangerous if you change entries of the returned dict.
         """
         d = self.fetch('dict')
-        if not d is None:
+        if d is not None:
             return d
 
         cdef Py_ssize_t i, j, k
@@ -311,10 +311,9 @@ cdef class Matrix_integer_sparse(Matrix_sparse):
             [0 1 0 0 0 0 1 0]
             sage: M._nonzero_positions_by_row()
             [(0, 3), (1, 1), (1, 6)]
-
         """
         x = self.fetch('nonzero_positions')
-        if not x is None:
+        if x is not None:
             if copy:
                 return list(x)
             return x
@@ -343,10 +342,9 @@ cdef class Matrix_integer_sparse(Matrix_sparse):
             [0 1 0 0 0 0 1 0]
             sage: M._nonzero_positions_by_column()
             [(1, 1), (0, 3), (1, 6)]
-
         """
         x = self.fetch('nonzero_positions_by_column')
-        if not x is None:
+        if x is not None:
             if copy:
                 return list(x)
             return x

src/sage/matrix/matrix_mod2_dense.pyx

@@ -1040,7 +1040,8 @@ cdef class Matrix_mod2_dense(matrix_dense.Matrix_dense):   # dense or sparse
         full = int(reduced)
 
         x = self.fetch('in_echelon_form')
-        if not x is None: return  # already known to be in echelon form
+        if x is not None:
+            return  # already known to be in echelon form
 
         if algorithm == 'heuristic':
 
@@ -1839,7 +1840,7 @@ cdef class Matrix_mod2_dense(matrix_dense.Matrix_dense):   # dense or sparse
             0
         """
         x = self.fetch('rank')
-        if not x is None:
+        if x is not None:
             return x
         if self._nrows == 0 or self._ncols == 0:
             return 0

src/sage/matrix/matrix_modn_sparse.pyx

@@ -231,7 +231,7 @@ cdef class Matrix_modn_sparse(matrix_sparse.Matrix_sparse):
             Finite Field of size 13
         """
         d = self.fetch('dict')
-        if not d is None:
+        if d is not None:
             return d
 
         cdef Py_ssize_t i, j, k
@@ -427,7 +427,8 @@ cdef class Matrix_modn_sparse(matrix_sparse.Matrix_sparse):
         """
         from sage.misc.verbose import verbose, get_verbose
         x = self.fetch('in_echelon_form')
-        if not x is None and x: return  # already known to be in echelon form
+        if x is not None and x:
+            return  # already known to be in echelon form
         self.check_mutability()
 
         cdef Py_ssize_t i, r, c, min, min_row,  start_row
@@ -501,7 +502,7 @@ cdef class Matrix_modn_sparse(matrix_sparse.Matrix_sparse):
             [(0, 3), (1, 1), (1, 6)]
         """
         x = self.fetch('nonzero_positions')
-        if not x is None:
+        if x is not None:
             if copy:
                 return list(x)
             return x