How does Python's super() work with multiple inheritance?

Question

I\'m pretty much new in Python object oriented programming and I have trouble understanding the super() function (new style classes) especially when it comes to

Answer 1

In python 3.5+ inheritance looks predictable and very nice for me. Please looks at this code:

class Base(object):
  def foo(self):
    print("    Base(): entering")
    print("    Base(): exiting")


class First(Base):
  def foo(self):
    print("   First(): entering Will call Second now")
    super().foo()
    print("   First(): exiting")


class Second(Base):
  def foo(self):
    print("  Second(): entering")
    super().foo()
    print("  Second(): exiting")


class Third(First, Second):
  def foo(self):
    print(" Third(): entering")
    super().foo()
    print(" Third(): exiting")


class Fourth(Third):
  def foo(self):
    print("Fourth(): entering")
    super().foo()
    print("Fourth(): exiting")

Fourth().foo()
print(Fourth.__mro__)

Outputs:

Fourth(): entering
 Third(): entering
   First(): entering Will call Second now
  Second(): entering
    Base(): entering
    Base(): exiting
  Second(): exiting
   First(): exiting
 Third(): exiting
Fourth(): exiting
(, , , , , )

As you can see, it calls foo exactly ONE time for each inherited chain in the same order as it was inherited. You can get that order by calling .mro :

Fourth -> Third -> First -> Second -> Base -> object