[QUESTION] Return class instance, but the class function get the wrong data

def atest()：
      my_BTD = py_cc.BTD(Nd, Np, sizebw, type)   # construct a c++ class
      a = my_BTD.get_array()                                  # this function get right data
      b = btest(my_BTD)                                        # this will get the right data      
                                                                             # a is same with b
     print(a)
     print(b)

return my_BTD 

a = atest()
c = a.get_array()                                        #this functtion get wrong data, sometimes get wrong data, sometime get right data 
print(c)

def btest(BTD):
      b = BTD.get_array()                                   # this function get right data

who can tell me why??? thanks a lot!

EDIT (@YannickJadoul): surround code with ```

Start with the atest and btest examples in the issue and reproduce the differing get_array() results after returning BTD. Inspect the BTD binding and get_array entry points, which are not included here; done requires a minimal reproducible case and an identified explanation or regression test for the inconsistent returned data.