[Python] Why this python code triggers RecursionError [closed]

I ran the following code and it triggered lots of repeated printouts and the RecursionEorr. Can someone help explain the reason please? Thank you!

The code

class Customer:
def __init__(self, id, name):
self.id=id
self.name=name

def __eq__(self, other):
print('simulated default __eq__ is called')
return self==other


c1=Customer(123, 'A')
c2=Customer(123, 'A')
print(c1==c2)


Part of the log

simulated default __eq__ is called
simulated default __eq__ is called
simulated default __eq__ is called
simulated default __eq__ is called
simulated default __eq__ is called
simulated default __eq__ is called
simulated default __eq__ is called
---------------------------------------------------------------------------
RecursionError Traceback (most recent call last)
Cell In[5], line 13
11 c1=Customer(123, 'A')
12 c2=Customer(123, 'A')
---> 13 print(c1==c2)

Cell In[5], line 8, in Customer.__eq__(self, other)
6 def __eq__(self, other):
7 print('simulated default __eq__ is called')
----> 8 return self==other

Cell In[5], line 8, in Customer.__eq__(self, other)
6 def __eq__(self, other):
7 print('simulated default __eq__ is called')
----> 8 return self==other

[... skipping similar frames: Customer.__eq__ at line 8 (990 times)]

Cell In[5], line 8, in Customer.__eq__(self, other)
6 def __eq__(self, other):
7 print('simulated default __eq__ is called')
----> 8 return self==other

Cell In[5], line 7, in Customer.__eq__(self, other)
6 def __eq__(self, other):
----> 7 print('simulated default __eq__ is called')
8 return self==other

File ~\AppData\Local\Programs\Python\Python313\Lib\site-packages\ipykernel\iostream.py:684, in OutStream.write(self, string)
682 # only touch the buffer in the IO thread to avoid races
683 with self._buffer_lock:
--> 684 self._buffers[frozenset(parent.items())].write(string)
685 if is_child:
686 # mp.Pool cannot be trusted to flush promptly (or ever),
687 # and this helps.
688 if self._subprocess_flush_pending:

RecursionError: maximum recursion depth exceeded in comparison


PS: I switched to use this code 'return self is other', which resolved the issue anyway.

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