diff --git a/src/sage/categories/pushout.py b/src/sage/categories/pushout.py
index f8aa1aa646a..5fbc590fb8e 100644
--- a/src/sage/categories/pushout.py
+++ b/src/sage/categories/pushout.py
@@ -1378,7 +1378,7 @@ def __mul__(self, other):
         # even respecting the order. Note that, if the pushout is computed, only *one* variable
         # will occur in the polynomial constructor. Hence, any order is fine, which is exactly
         # what we need in order to have coercion maps for different orderings.
-        if isinstance(other, MultiPolynomialFunctor) or isinstance(other, PolynomialFunctor):
+        if isinstance(other, (MultiPolynomialFunctor, PolynomialFunctor)):
             if isinstance(other, MultiPolynomialFunctor):
                 othervars = other.vars
             else:
diff --git a/src/sage/dynamics/arithmetic_dynamics/affine_ds.py b/src/sage/dynamics/arithmetic_dynamics/affine_ds.py
index a4f03f439bf..ec130e75a3b 100644
--- a/src/sage/dynamics/arithmetic_dynamics/affine_ds.py
+++ b/src/sage/dynamics/arithmetic_dynamics/affine_ds.py
@@ -718,7 +718,7 @@ def orbit(self, P, n):
              ((-t^16 + 3*t^13 - 3*t^10 + t^7 + t^5 + t^3 - 1)/(t^5 + t^3 - 1), -t^9 - t^7 + t^4)]
         """
         Q = P
-        if isinstance(n, list) or isinstance(n, tuple):
+        if isinstance(n, (list, tuple)):
             bounds = list(n)
         else:
             bounds = [0,n]
diff --git a/src/sage/geometry/polyhedron/backend_normaliz.py b/src/sage/geometry/polyhedron/backend_normaliz.py
index f932b0081c4..9d109238df1 100644
--- a/src/sage/geometry/polyhedron/backend_normaliz.py
+++ b/src/sage/geometry/polyhedron/backend_normaliz.py
@@ -1196,7 +1196,7 @@ def format_number(x):
                 return '({})'.format(x.polynomial('a'))
 
         def format_field(key, value):
-            if isinstance(value, list) or isinstance(value, tuple):
+            if isinstance(value, (list, tuple)):
                 s = '{} {}\n'.format(key, len(value))
                 for e in value:
                     for x in e:
diff --git a/src/sage/interfaces/maxima_lib.py b/src/sage/interfaces/maxima_lib.py
index 449f9751abf..8d2cbf5dad0 100644
--- a/src/sage/interfaces/maxima_lib.py
+++ b/src/sage/interfaces/maxima_lib.py
@@ -1589,7 +1589,7 @@ def sr_to_max(expr):
     """
     global sage_op_dict, max_op_dict
     global sage_sym_dict, max_sym_dict
-    if isinstance(expr,list) or isinstance(expr,tuple):
+    if isinstance(expr, (list, tuple)):
         return EclObject(([mlist],[sr_to_max(e) for e in expr]))
     op = expr.operator()
     if op:
diff --git a/src/sage/libs/giac/giac.pyx b/src/sage/libs/giac/giac.pyx
index b9811cae273..e095ab70ec0 100644
--- a/src/sage/libs/giac/giac.pyx
+++ b/src/sage/libs/giac/giac.pyx
@@ -978,7 +978,7 @@ cdef class Pygen(GiacMethods_base):
         cdef gen result
 
         if(self._type == 7) or (self._type == 12):   #if self is a list or a string
-            if isinstance(i,int) or isinstance(i,Integer):
+            if isinstance(i, (int, Integer)):
                 n=len(self)
                 if(i<n)and(-i<=n):
                     if(i<0):
diff --git a/src/sage/libs/mpmath/ext_main.pyx b/src/sage/libs/mpmath/ext_main.pyx
index 31f116f9deb..7ba4fb1c17b 100644
--- a/src/sage/libs/mpmath/ext_main.pyx
+++ b/src/sage/libs/mpmath/ext_main.pyx
@@ -127,7 +127,7 @@ cdef int MPF_set_any(MPF *re, MPF *im, x, MPopts opts, bint str_tuple_ok) except
         MPF_set(re, &(<mpc>x).re)
         MPF_set(im, &(<mpc>x).im)
         return 2
-    if isinstance(x, int) or isinstance(x, long) or isinstance(x, Integer):
+    if isinstance(x, (int, Integer)):
         MPF_set_int(re, x)
         return 1
     if isinstance(x, float):
@@ -995,7 +995,7 @@ cdef class Context:
         """
         cdef MPF v
         cdef bint ismpf, ismpc
-        if isinstance(x, int) or isinstance(x, long) or isinstance(x, Integer):
+        if isinstance(x, (int, Integer)):
             return int(x), 'Z'
         if isinstance(x, tuple):
             p, q = x
@@ -1072,7 +1072,7 @@ cdef class Context:
 
         """
         cdef int typ
-        if isinstance(x, int) or isinstance(x, long) or isinstance(x, Integer):
+        if isinstance(x, (int, Integer)):
             mpz_set_integer(tmp_opx_re.man, x)
             if mpz_sgn(tmp_opx_re.man) == 0:
                 return global_context.ninf
diff --git a/src/sage/libs/mpmath/utils.pyx b/src/sage/libs/mpmath/utils.pyx
index f7b50db3c36..466334e929a 100644
--- a/src/sage/libs/mpmath/utils.pyx
+++ b/src/sage/libs/mpmath/utils.pyx
@@ -334,7 +334,7 @@ def sage_to_mpmath(x, prec):
                 from sage.rings.complex_mpfr import ComplexField
                 x = ComplexField(prec)(x)
                 return x._mpmath_()
-    if isinstance(x, tuple) or isinstance(x, list):
+    if isinstance(x, (tuple, list)):
         return type(x)([sage_to_mpmath(v, prec) for v in x])
     if isinstance(x, dict):
         return dict([(k, sage_to_mpmath(v, prec)) for (k, v) in x.items()])
diff --git a/src/sage/libs/ntl/ntl_GF2.pyx b/src/sage/libs/ntl/ntl_GF2.pyx
index b899f21548f..605bd3ad936 100644
--- a/src/sage/libs/ntl/ntl_GF2.pyx
+++ b/src/sage/libs/ntl/ntl_GF2.pyx
@@ -56,7 +56,7 @@ cdef class ntl_GF2(object):
         """
         if isinstance(v, ntl_GF2):
             self.x = (<ntl_GF2>v).x
-        elif isinstance(v, int) or isinstance(v, long) or isinstance(v, Integer):
+        elif isinstance(v, (int, Integer)):
             GF2_conv_long(self.x, int(v) % 2)
         elif v is not None:
             ccreadstr(self.x, str(v))
diff --git a/src/sage/libs/ntl/ntl_ZZX.pyx b/src/sage/libs/ntl/ntl_ZZX.pyx
index ac3e3d10271..8c596bd23a6 100644
--- a/src/sage/libs/ntl/ntl_ZZX.pyx
+++ b/src/sage/libs/ntl/ntl_ZZX.pyx
@@ -131,7 +131,7 @@ cdef class ntl_ZZX(object):
 
         if v is None:
             return
-        elif isinstance(v, list) or isinstance(v, tuple):
+        elif isinstance(v, (list, tuple)):
             for i from 0 <= i < len(v):
                 x = v[i]
                 if not isinstance(x, ntl_ZZ):
diff --git a/src/sage/libs/ntl/ntl_ZZ_pE.pyx b/src/sage/libs/ntl/ntl_ZZ_pE.pyx
index c2802a3391b..6e3684521de 100644
--- a/src/sage/libs/ntl/ntl_ZZ_pE.pyx
+++ b/src/sage/libs/ntl/ntl_ZZ_pE.pyx
@@ -113,7 +113,7 @@ cdef class ntl_ZZ_pE(object):
                 if (<ntl_ZZ_pX>v).c is not self.c.pc:
                     raise ValueError("You cannot cast between rings with different moduli")
                 self.x = ZZ_pX_to_ZZ_pE((<ntl_ZZ_pX>v).x)
-            elif isinstance(v, list) or isinstance(v, tuple):
+            elif isinstance(v, (list, tuple)):
                 tmp_zzpx = <ntl_ZZ_pX>ntl_ZZ_pX(v, self.c.pc)
                 self.c.restore_c()   # allocating tmp_zzpx can change the current modulus trac #25790
                 self.x = ZZ_pX_to_ZZ_pE(tmp_zzpx.x)
diff --git a/src/sage/libs/ntl/ntl_ZZ_pEX.pyx b/src/sage/libs/ntl/ntl_ZZ_pEX.pyx
index b83d6f062f1..a23d84bd4ad 100644
--- a/src/sage/libs/ntl/ntl_ZZ_pEX.pyx
+++ b/src/sage/libs/ntl/ntl_ZZ_pEX.pyx
@@ -87,7 +87,7 @@ cdef class ntl_ZZ_pEX(object):
 
         if v is None:
             return
-        elif isinstance(v, list) or isinstance(v, tuple):
+        elif isinstance(v, (list, tuple)):
             for i from 0 <= i < len(v):
                 x = v[i]
                 if not isinstance(x, ntl_ZZ_pE):
diff --git a/src/sage/libs/singular/function.pyx b/src/sage/libs/singular/function.pyx
index ddb4fdad783..698cc81f2ad 100644
--- a/src/sage/libs/singular/function.pyx
+++ b/src/sage/libs/singular/function.pyx
@@ -531,7 +531,7 @@ cdef class Converter(SageObject):
                     isinstance(a, NCPolynomialIdeal):
                 v = self.append_ideal(a)
 
-            elif isinstance(a, int) or isinstance(a, long):
+            elif isinstance(a, int):
                 v = self.append_int(a)
 
             elif isinstance(a, str):
@@ -1427,8 +1427,7 @@ The Singular documentation for '%s' is given below.
                 continue
             elif isinstance(a, Matrix_mpolynomial_dense):
                 ring2 = a.base_ring()
-            elif isinstance(a, list) or isinstance(a, tuple)\
-                or isinstance(a, Sequence_generic):
+            elif isinstance(a, (list, tuple, Sequence_generic)):
                 #TODO: catch exception, if recursion finds no ring
                 ring2 = self.common_ring(tuple(a), ring)
             elif isinstance(a, Resolution):
diff --git a/src/sage/matroids/utilities.py b/src/sage/matroids/utilities.py
index 751d96592b2..eb2999ea07b 100644
--- a/src/sage/matroids/utilities.py
+++ b/src/sage/matroids/utilities.py
@@ -123,7 +123,7 @@ def setprint_s(X, toplevel=False):
         sage: setprint_s(X, toplevel=True)
         'abcd'
     """
-    if isinstance(X, frozenset) or isinstance(X, set):
+    if isinstance(X, (frozenset, set)):
         return '{' + ', '.join(sorted(setprint_s(x) for x in X)) + '}'
     elif isinstance(X, dict):
         return '{' + ', '.join(sorted(setprint_s(key) + ': ' + setprint_s(val)
diff --git a/src/sage/modular/cusps.py b/src/sage/modular/cusps.py
index ef1b8e250d6..0a40b57294c 100644
--- a/src/sage/modular/cusps.py
+++ b/src/sage/modular/cusps.py
@@ -214,7 +214,7 @@ def __init__(self, a, b=None, parent=None, check=True):
             self.__b = ZZ.zero()
             return
 
-        if isinstance(a, Integer) or isinstance(a, Rational):
+        if isinstance(a, (Integer, Rational)):
             r = a / ZZ(b)
         elif is_InfinityElement(a):
             self.__a = ZZ.one()
diff --git a/src/sage/modular/modform_hecketriangle/analytic_type.py b/src/sage/modular/modform_hecketriangle/analytic_type.py
index 9b80337749f..00207502ad4 100644
--- a/src/sage/modular/modform_hecketriangle/analytic_type.py
+++ b/src/sage/modular/modform_hecketriangle/analytic_type.py
@@ -528,7 +528,7 @@ def _element_constructor_(self, element):
 
         if isinstance(element, str):
             element=[element]
-        if isinstance(element,list) or isinstance(element,tuple):
+        if isinstance(element, (list, tuple)):
             element = Set(self._base_poset.order_ideal([self._base_poset(s) for s in element]))
 
         return super(AnalyticType, self)._element_constructor_(element)
diff --git a/src/sage/modular/modform_hecketriangle/subspace.py b/src/sage/modular/modform_hecketriangle/subspace.py
index 853d4ecfb9c..758a154f14b 100644
--- a/src/sage/modular/modform_hecketriangle/subspace.py
+++ b/src/sage/modular/modform_hecketriangle/subspace.py
@@ -84,7 +84,7 @@ def ModularFormsSubSpace(*args, **kwargs):
 
     generators = []
     for arg in args:
-        if isinstance(arg, list) or isinstance(arg, tuple):
+        if isinstance(arg, (list, tuple)):
             generators += arg
         else:
             generators.append(arg)
diff --git a/src/sage/modules/vector_mod2_dense.pyx b/src/sage/modules/vector_mod2_dense.pyx
index 8389d851239..61ae0eb1a69 100644
--- a/src/sage/modules/vector_mod2_dense.pyx
+++ b/src/sage/modules/vector_mod2_dense.pyx
@@ -505,7 +505,7 @@ def unpickle_v0(parent, entries, degree, is_immutable):
     cdef int xi
 
     for i from 0 <= i < degree:
-        if isinstance(entries[i], IntegerMod_int) or isinstance(entries[i], int) or isinstance(entries[i], Integer):
+        if isinstance(entries[i], (IntegerMod_int, int, Integer)):
             xi = entries[i]
             mzd_write_bit(v._entries, 0, i, xi%2)
         else:
diff --git a/src/sage/numerical/mip.pyx b/src/sage/numerical/mip.pyx
index 05c2de57742..541361b90a9 100644
--- a/src/sage/numerical/mip.pyx
+++ b/src/sage/numerical/mip.pyx
@@ -1004,7 +1004,7 @@ cdef class MixedIntegerLinearProgram(SageObject):
             indices = list(xrange(b.nrows()))
 
         # Only one constraint
-        if isinstance(indices, int) or isinstance(indices, Integer):
+        if isinstance(indices, (int, Integer)):
             lb, ub = b.row_bounds(indices)
             return (lb, b.row(indices), ub)
 
diff --git a/src/sage/numerical/optimize.py b/src/sage/numerical/optimize.py
index ecb1304a98f..7a24fb6ab55 100644
--- a/src/sage/numerical/optimize.py
+++ b/src/sage/numerical/optimize.py
@@ -542,8 +542,8 @@ def minimize_constrained(func,cons,x0,gradient=None,algorithm='default', **args)
     else:
         f = func
 
-    if isinstance(cons,list):
-        if isinstance(cons[0], tuple) or isinstance(cons[0], list) or cons[0] is None:
+    if isinstance(cons, list):
+        if isinstance(cons[0], (tuple, list)) or cons[0] is None:
             if gradient is not None:
                 if algorithm == 'l-bfgs-b':
                     min = optimize.fmin_l_bfgs_b(f, x0, gradient, bounds=cons, iprint=-1, **args)[0]
@@ -554,7 +554,7 @@ def minimize_constrained(func,cons,x0,gradient=None,algorithm='default', **args)
                     min = optimize.fmin_l_bfgs_b(f, x0, approx_grad=True, bounds=cons, iprint=-1, **args)[0]
                 else:
                     min = optimize.fmin_tnc(f, x0, approx_grad=True, bounds=cons, messages=0, **args)[0]
-        elif isinstance(cons[0], function_type) or isinstance(cons[0], Expression):
+        elif isinstance(cons[0], (function_type, Expression)):
             min = optimize.fmin_cobyla(f, x0, cons, **args)
     elif isinstance(cons, function_type) or isinstance(cons, Expression):
         min = optimize.fmin_cobyla(f, x0, cons, **args)
diff --git a/src/sage/rings/complex_mpc.pyx b/src/sage/rings/complex_mpc.pyx
index 8cf8c6344fb..49109af92c6 100644
--- a/src/sage/rings/complex_mpc.pyx
+++ b/src/sage/rings/complex_mpc.pyx
@@ -846,7 +846,7 @@ cdef class MPComplexNumber(sage.structure.element.FieldElement):
                 return
             elif isinstance(z, sage.libs.pari.all.pari_gen):
                 real, imag = z.real(), z.imag()
-            elif isinstance(z, list) or isinstance(z, tuple):
+            elif isinstance(z, (list, tuple)):
                 real, imag = z
             elif isinstance(z, complex):
                 real, imag = z.real, z.imag
diff --git a/src/sage/rings/complex_mpfr.pyx b/src/sage/rings/complex_mpfr.pyx
index 62b58ce8c8e..21b32326aa3 100644
--- a/src/sage/rings/complex_mpfr.pyx
+++ b/src/sage/rings/complex_mpfr.pyx
@@ -958,7 +958,7 @@ cdef class ComplexNumber(sage.structure.element.FieldElement):
                 real, imag = (<ComplexNumber>real).real(), (<ComplexNumber>real).imag()
             elif isinstance(real, sage.libs.pari.all.pari_gen):
                 real, imag = real.real(), real.imag()
-            elif isinstance(real, list) or isinstance(real, tuple):
+            elif isinstance(real, (list, tuple)):
                 re, imag = real
                 real = re
             elif isinstance(real, complex):
diff --git a/src/sage/rings/convert/mpfi.pyx b/src/sage/rings/convert/mpfi.pyx
index 1f16b866862..3dbe12da224 100644
--- a/src/sage/rings/convert/mpfi.pyx
+++ b/src/sage/rings/convert/mpfi.pyx
@@ -86,7 +86,7 @@ cdef int mpfi_set_sage(mpfi_ptr re, mpfi_ptr im, x, field, int base) except -1:
         mpfi_set_sage(re, NULL, x[0], field, base)
         mpfi_set_sage(im, NULL, x[1], field, base)
         return 0
-    if isinstance(x, list) or isinstance(x, tuple):
+    if isinstance(x, (list, tuple)):
         # Interpret entries in x as endpoints of interval
         if len(x) != 2:
             raise TypeError("list defining an interval must have length 2")
diff --git a/src/sage/rings/finite_rings/element_ntl_gf2e.pyx b/src/sage/rings/finite_rings/element_ntl_gf2e.pyx
index f6d6ec9c446..beda02aea78 100644
--- a/src/sage/rings/finite_rings/element_ntl_gf2e.pyx
+++ b/src/sage/rings/finite_rings/element_ntl_gf2e.pyx
@@ -308,9 +308,7 @@ cdef class Cache_ntl_gf2e(Cache_base):
 
         if is_IntegerMod(e):
             e = e.lift()
-        if isinstance(e, int) or \
-             isinstance(e, Integer) or \
-             isinstance(e, long):
+        if isinstance(e, (int, Integer)):
             GF2E_conv_long(res.x,int(e&1))
             return res
 
diff --git a/src/sage/rings/polynomial/groebner_fan.py b/src/sage/rings/polynomial/groebner_fan.py
index f35af7630bb..6c6548d9e85 100644
--- a/src/sage/rings/polynomial/groebner_fan.py
+++ b/src/sage/rings/polynomial/groebner_fan.py
@@ -1331,7 +1331,7 @@ def render(self, file=None, larger=False, shift=0, rgbcolor=(0, 0, 0),
             r_lines = r_lines + line(x, rgbcolor=rgbcolor)
         if polyfill:
             vals = [polyfill(q) for q in self.reduced_groebner_bases()]
-            if isinstance(vals[0], list) or isinstance(vals[0], tuple):
+            if isinstance(vals[0], (list, tuple)):
                 if scale_colors:
                     vmins = [min([q[i] for q in vals]) for i in (0, 1, 2)]
                     vmaxs = [max([q[i] for q in vals]) for i in (0, 1, 2)]
diff --git a/src/sage/rings/polynomial/pbori/pbori.pyx b/src/sage/rings/polynomial/pbori/pbori.pyx
index 95c13e82872..f8c9771e51a 100644
--- a/src/sage/rings/polynomial/pbori/pbori.pyx
+++ b/src/sage/rings/polynomial/pbori/pbori.pyx
@@ -8165,7 +8165,7 @@ cdef class PolynomialFactory:
             elif isinstance(ring, BooleanPolynomialRing):
                 return (<BooleanPolynomialRing>ring).coerce(arg)
         else:
-            if isinstance(arg, int) or isinstance(arg, Integer):
+            if isinstance(arg, (int, Integer)):
                 return new_BP_from_PBPoly(self._ring,
                                           self._factory(<long>arg))
 
diff --git a/src/sage/rings/polynomial/polynomial_zmod_flint.pyx b/src/sage/rings/polynomial/polynomial_zmod_flint.pyx
index 3fe6f33c18d..748d8ce37c7 100644
--- a/src/sage/rings/polynomial/polynomial_zmod_flint.pyx
+++ b/src/sage/rings/polynomial/polynomial_zmod_flint.pyx
@@ -100,7 +100,7 @@ cdef class Polynomial_zmod_flint(Polynomial_template):
         """
         cdef long nlen
 
-        if isinstance(x, list) or isinstance(x, tuple):
+        if isinstance(x, (list, tuple)):
             k = parent._base
             if check:
                 lst = [k(i) for i in x]
diff --git a/src/sage/rings/polynomial/polynomial_zz_pex.pyx b/src/sage/rings/polynomial/polynomial_zz_pex.pyx
index 5db4b9d84d4..853ca0629c3 100644
--- a/src/sage/rings/polynomial/polynomial_zz_pex.pyx
+++ b/src/sage/rings/polynomial/polynomial_zz_pex.pyx
@@ -138,7 +138,7 @@ cdef class Polynomial_ZZ_pEX(Polynomial_template):
         if isinstance(x, Polynomial):
             x = x.list()
 
-        if isinstance(x, list) or isinstance(x, tuple):
+        if isinstance(x, (list, tuple)):
             Polynomial.__init__(self, parent, is_gen=is_gen)
             (<Polynomial_template>self)._cparent = get_cparent(parent)
             celement_construct(&self.x, (<Polynomial_template>self)._cparent)
diff --git a/src/sage/rings/polynomial/term_order.py b/src/sage/rings/polynomial/term_order.py
index 64cdec1443e..6763f2016c7 100644
--- a/src/sage/rings/polynomial/term_order.py
+++ b/src/sage/rings/polynomial/term_order.py
@@ -706,7 +706,7 @@ def __init__(self, name='lex', n=0, force=False):
             name = name.lower()
         else:
             try:
-                if not isinstance(name, (tuple,list)):
+                if not isinstance(name, (tuple, list)):
                     name = name.list() # name may be a matrix
                 name = tuple(name)
             except Exception:
@@ -766,7 +766,8 @@ def __init__(self, name='lex', n=0, force=False):
             self._macaulay2_str = "{" + ",".join(macaulay2_str) + "}"
             self._magma_str = "" # Magma does not support block order
             self._blocks = tuple(blocks)
-        elif isinstance(name, str) and not (isinstance(n, tuple) or isinstance(n,list)): # string representation of simple or block orders
+        elif isinstance(name, str) and not isinstance(n, (tuple, list)):
+            # string representation of simple or block orders
             if force:
                 self._length = n
                 self._name = name
@@ -817,7 +818,8 @@ def __init__(self, name='lex', n=0, force=False):
                     if n and length != n:
                         raise ValueError("term order length does not match the number of generators")
                     self.__copy(TermOrder('block', blocks))
-        elif isinstance(name, str) and (isinstance(n, tuple) or isinstance(n,list)): # weighted degree term orders
+        elif isinstance(name, str) and isinstance(n, (tuple, list)):
+            # weighted degree term orders
             if name not in print_name_mapping.keys() and name not in singular_name_mapping.values() and not force:
                 raise ValueError("unknown term order {!r}".format(name))
             weights = tuple(int(w) for w in n) # n is a tuple of weights
diff --git a/src/sage/sandpiles/sandpile.py b/src/sage/sandpiles/sandpile.py
index 8270261cbe3..da3955bf6f2 100644
--- a/src/sage/sandpiles/sandpile.py
+++ b/src/sage/sandpiles/sandpile.py
@@ -593,7 +593,7 @@ def __init__(self, g, sink=None):
             TypeError: ...__init__() got an unexpected keyword argument 'weighted'
         """
         # set graph name
-        if isinstance(g, Graph) or isinstance(g, DiGraph):
+        if isinstance(g, (Graph, DiGraph)):
             name = g.name()
             if name == '':
                 name = 'sandpile graph'
@@ -612,7 +612,7 @@ def __init__(self, g, sink=None):
         elif isinstance(g, dict) and isinstance(next(iter(g.values())), list):
             processed_g = {i: dict(Counter(g[i])) for i in g}
             g = processed_g
-        elif isinstance(g, Graph) or isinstance(g, DiGraph):
+        elif isinstance(g, (Graph, DiGraph)):
             if not g.weighted():
                 h = g.to_dictionary(multiple_edges=True)
                 g = {i: dict(Counter(h[i])) for i in h}
@@ -2254,7 +2254,7 @@ def markov_chain(self,state, distrib=None):
         st = deepcopy(state)
         V = self.vertices()
         n = len(V)
-        if isinstance(st,list):
+        if isinstance(st, list):
             if len(st)==self.num_verts()-1:
                 st = SandpileConfig(self,st)
             elif len(st)==self.num_verts():
@@ -2264,7 +2264,7 @@ def markov_chain(self,state, distrib=None):
         if distrib is None:  # default = uniform distribution
             distrib = [QQ.one() / n] * n
         X = GeneralDiscreteDistribution(distrib)
-        if isinstance(st,SandpileConfig):
+        if isinstance(st, SandpileConfig):
             while True:
                 i = X.get_random_element()
                 if V[i] != self.sink():
@@ -2963,7 +2963,7 @@ def __init__(self, S, c):
             {1: 2, 2: 2, 3: 0}
         """
         if len(c)==S.num_verts()-1:
-            if isinstance(c, dict) or isinstance(c, SandpileConfig):
+            if isinstance(c, (dict, SandpileConfig)):
                 dict.__init__(self,c)
             elif isinstance(c, list):
                 c.reverse()
diff --git a/src/sage/schemes/berkovich/berkovich_cp_element.py b/src/sage/schemes/berkovich/berkovich_cp_element.py
index 1f868be527d..9587901c476 100644
--- a/src/sage/schemes/berkovich/berkovich_cp_element.py
+++ b/src/sage/schemes/berkovich/berkovich_cp_element.py
@@ -88,7 +88,7 @@ def __init__(self, parent, center, radius=None, power=None, prec=20, space_type=
         self._type = None
 
         # if radius is a list or a tuple, this is a type 4 point
-        if isinstance(radius, list) or isinstance(radius, tuple):
+        if isinstance(radius, (list, tuple)):
             if error_check:
                 if not (isinstance(center, list) or isinstance(center, tuple)):
                     raise TypeError("center was passed a list but radius was not a list")
diff --git a/src/sage/schemes/plane_conics/con_rational_field.py b/src/sage/schemes/plane_conics/con_rational_field.py
index d24bd59898c..5c35f342c14 100644
--- a/src/sage/schemes/plane_conics/con_rational_field.py
+++ b/src/sage/schemes/plane_conics/con_rational_field.py
@@ -230,7 +230,7 @@ def is_locally_solvable(self, p) -> bool:
             return True
         a = -abc[0] / abc[2]
         b = -abc[1] / abc[2]
-        if isinstance(p, sage.rings.abc.RealField) or isinstance(p, InfinityElement):
+        if isinstance(p, (sage.rings.abc.RealField, InfinityElement)):
             p = -1
         elif isinstance(p, Map) and p.category_for().is_subcategory(Rings()):
             # p is a morphism of Rings
diff --git a/src/sage/stats/time_series.pyx b/src/sage/stats/time_series.pyx
index 234925fb478..7045ed8b09d 100644
--- a/src/sage/stats/time_series.pyx
+++ b/src/sage/stats/time_series.pyx
@@ -131,7 +131,7 @@ cdef class TimeSeries:
         if isinstance(values, (int, long, Integer)):
             self._length = values
             values = None
-        elif isinstance(values, Vector_real_double_dense) or isinstance(values, cnumpy.ndarray):
+        elif isinstance(values, (Vector_real_double_dense, cnumpy.ndarray)):
             if isinstance(values, Vector_real_double_dense):
                 np  = values._vector_numpy
             else:
diff --git a/src/sage/structure/parent.pyx b/src/sage/structure/parent.pyx
index 483ca9b776e..0c97d4622c6 100644
--- a/src/sage/structure/parent.pyx
+++ b/src/sage/structure/parent.pyx
@@ -1740,7 +1740,7 @@ cdef class Parent(sage.structure.category_object.CategoryObject):
                 raise ValueError("Map's codomain must be self")
             self._convert_from_list.append(mor)
             self._convert_from_hash.set(mor.domain(), mor)
-        elif isinstance(mor, Parent) or isinstance(mor, type):
+        elif isinstance(mor, (Parent, type)):
             t = mor
             mor = self._generic_convert_map(mor)
             self._convert_from_list.append(mor)