Undefined behavior in python

The bytecode module is required (to generate bytecode).

import types import bytecode from bytecode import ConcreteInstr code = bytecode.Bytecode() code.append(ConcreteInstr('POP_TOP')) stop_signal = types.FunctionType(code.to_code(), {}) stop_signal() #в доках питона не сказано что здесь произойдет сегфолт.(хотя это известно) 

Python gives out 10, in it there is no increment in such type:

  i = 5 i = ++i + ++i print i class Foo: def __init__(self, num): self.num = num def inc(self): self.num += 1 return self.num i = Foo(5) print(i.inc() + i.inc()) 

because the interpreter calculates everything in order. But if you think a bit and bring everything to a logical mind, then all the same 14

 class Foo: def __init__(self, num): self.num = num def inc(self): self.num += 1 return self def __add__(self, right): return Foo(self.num + right.num) def __repr__(self): return repr(self.num) i = Foo(5) print(i.inc() + i.inc())