Strip `>>>` and `...` when pasting to REPL

Feature or enhancement

Proposal:

I often find myself wanting to paste some REPL code straight into the REPL, but both >>> and ... are preserved, and I have to manually cut those.

Let's consider stripping these automatically omitting the outputs, if the current prompt is empty.

E.g.

I copy this text:

>>> class A(object):
...     def __new__(self):
...         raise TypeError('i do not exist')
... 
>>> class B(A):
...     __new__ = object.__new__
...     def __init__(self, x):
...         self.x = x
... 
>>> B(1)

In the REPL, I'm not inside a string or anything:

>>>

I paste the text:

>>> class A(object):
...     def __new__(self):
...         raise TypeError('i do not exist')
... 
... class B(A):
...     __new__ = object.__new__
...     def __init__(self, x):
...         self.x = x
... 
... B(1)

Now I can edit it and run it.

This feature is a UX convenience and rough edges are expected:

• >>> and ... are conventional prompt strings that I think are fine to hardcode (practicality beats purity)
• lines from stdout starting with >>> or ... will be detected as REPL lines, but I don't think it's a problem at all
• there are slight semantic differences around sys.displayhook and builtins._

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-157615