Confusion with Ellipsis in Python

Question

In [81]: a
Out[81]: [[...]]

In [82]: b
Out[82]: [[Ellipsis]]

In [83]: a==b
Out[83]: False

In [84]: ...==Ellipsis
Out[84]: True

Why it is that when Ellipsis are in lists they are not equal, and when they are by themselves they are equal?

Answer 1

Check that

>>> [[...]] == [[Ellipsis]]
True

but

>>> a = []
>>> a.append(a)
>>> a
[<Recursion on list with id=70796424>]
>>> print(a)
[[...]]
>>> a==[[Ellipsis]]
False
>>> 

which is expected because you're comparing the Ellipsis object with an ellipsis representation of a recursively defined list.