class A: pass
class B(A): pass 
class C1(A): pass 
class C2: pass
class D1(B, C1): pass
class D2(B, C2): pass

X = list(D1.__mro__)
Y = list(D2.__mro__)
print(X[3] is Y[2])

int(2) is 2 * True

class A: attr = 1  
class B(A): pass
class C(B): pass
class D(A): attr = 2
class E(C, D): attr = C.attr  
x = E()
print(x.attr)

a = type([1, 2, 3]) == type(list)
b = [1, 2, 3].__class__ == list.__class__
print(a, b)

class A: attr = 1  
class B(A): pass     
class С(A): attr = 2
class D(B, С): pass   
x = D()
print(x.attr)

isinstance(type, object) + isinstance(object, type) + (type is object)

class С: pass 
c = С() 
a = type(c) == c.__class__
b = type(type(c)) is c.__class__.__class__
print(a, b)

f = type
print(f(f(f(f(f(None))))) is f )

class A:
    x = 'python'
    def __getitem__(self, i):
        return getattr(self.x, '__getitem__')(i) * 2
    def __getattr__(self, attr):
        return getattr(self.x, attr)
a = A()
print(a[0] + a.upper()[1:])

from functools import reduce
print(reduce(lambda acc, x: x * acc, [1,2,3,4], 1))