Fix test_ipdb_magics doctest for Python 3.13

IPython/core/tests/test_debugger.py

@@ -59,40 +59,43 b' def test_ipdb_magics():'
 
     First, set up some test functions and classes which we can inspect.
 
-    >>> class ExampleClass(object):
-    ...    """Docstring for ExampleClass."""
-    ...    def __init__(self):
-    ...        """Docstring for ExampleClass.__init__"""
-    ...        pass
-    ...    def __str__(self):
-    ...        return "ExampleClass()"
+    In [1]: class ExampleClass(object):
+       ...:    """Docstring for ExampleClass."""
+       ...:    def __init__(self):
+       ...:        """Docstring for ExampleClass.__init__"""
+       ...:        pass
+       ...:    def __str__(self):
+       ...:        return "ExampleClass()"
 
-    >>> def example_function(x, y, z="hello"):
-    ...     """Docstring for example_function."""
-    ...     pass
+    In [2]: def example_function(x, y, z="hello"):
+       ...:     """Docstring for example_function."""
+       ...:     pass
 
-    >>> old_trace = sys.gettrace()
+    In [3]: old_trace = sys.gettrace()
 
     Create a function which triggers ipdb.
 
-    >>> def trigger_ipdb():
-    ...    a = ExampleClass()
-    ...    debugger.Pdb().set_trace()
-
-    >>> with PdbTestInput([
-    ...    'pdef example_function',
-    ...    'pdoc ExampleClass',
-    ...    'up',
-    ...    'down',
-    ...    'list',
-    ...    'pinfo a',
-    ...    'll',
-    ...    'continue',
-    ... ]):
-    ...     trigger_ipdb()
-    --Return--
-    None
-    > <doctest ...>(3)trigger_ipdb()
+    In [4]: def trigger_ipdb():
+       ...:    a = ExampleClass()
+       ...:    debugger.Pdb().set_trace()
+
+    Run ipdb with faked input & check output. Because of a difference between
+    Python 3.13 & older versions, the first bit of the output is inconsistent.
+    We need to use ... to accommodate that, so the examples have to use IPython
+    prompts so that ... is distinct from the Python PS2 prompt.
+
+    In [5]: with PdbTestInput([
+       ...:    'pdef example_function',
+       ...:    'pdoc ExampleClass',
+       ...:    'up',
+       ...:    'down',
+       ...:    'list',
+       ...:    'pinfo a',
+       ...:    'll',
+       ...:    'continue',
+       ...: ]):
+       ...:     trigger_ipdb()
+    ...> <doctest ...>(3)trigger_ipdb()
           1 def trigger_ipdb():
           2    a = ExampleClass()
     ----> 3    debugger.Pdb().set_trace()
@@ -112,8 +115,7 b' def test_ipdb_magics():'
          10 ]):
     ---> 11     trigger_ipdb()
     <BLANKLINE>
-    ipdb> down
-    None
+    ipdb> down...
     > <doctest ...>(3)trigger_ipdb()
           1 def trigger_ipdb():
           2    a = ExampleClass()
@@ -139,7 +141,7 b' def test_ipdb_magics():'
     
     Restore previous trace function, e.g. for coverage.py    
     
-    >>> sys.settrace(old_trace)
+    In [6]: sys.settrace(old_trace)
     '''
 
 def test_ipdb_magics2():