Crash when trying to show globals() (__repr__ returned non-string)

[trag1c]

Keywords searched: globals, __repr__

λ ~ :: ipython
Python 3.12.0 (main, Oct 20 2023, 00:04:04) [Clang 15.0.0 (clang-1500.0.40.1)]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.24.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: globals()
Out[1]: ---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
File ~/.pyenv/versions/3.12.0/lib/python3.12/site-packages/IPython/core/formatters.py:711, in PlainTextFormatter.__call__(self, obj)
    704 stream = StringIO()
    705 printer = pretty.RepresentationPrinter(stream, self.verbose,
    706     self.max_width, self.newline,
    707     max_seq_length=self.max_seq_length,
    708     singleton_pprinters=self.singleton_printers,
    709     type_pprinters=self.type_printers,
    710     deferred_pprinters=self.deferred_printers)
--> 711 printer.pretty(obj)
    712 printer.flush()
    713 return stream.getvalue()

File ~/.pyenv/versions/3.12.0/lib/python3.12/site-packages/IPython/lib/pretty.py:394, in RepresentationPrinter.pretty(self, obj)
    391 for cls in _get_mro(obj_class):
    392     if cls in self.type_pprinters:
    393         # printer registered in self.type_pprinters
--> 394         return self.type_pprinters[cls](obj, self, cycle)
    395     else:
    396         # deferred printer
    397         printer = self._in_deferred_types(cls)

File ~/.pyenv/versions/3.12.0/lib/python3.12/site-packages/IPython/lib/pretty.py:693, in _dict_pprinter_factory.<locals>.inner(obj, p, cycle)
    691
    692     p.text(': ')
--> 693     p.pretty(obj[key])
    694 p.end_group(step, end)

File ~/.pyenv/versions/3.12.0/lib/python3.12/site-packages/IPython/lib/pretty.py:411, in RepresentationPrinter.pretty(self, obj)
    408                         return meth(obj, self, cycle)
    409                 if cls is not object \
    410                         and callable(cls.__dict__.get('__repr__')):
--> 411                     return _repr_pprint(obj, self, cycle)
    413     return _default_pprint(obj, self, cycle)
    414 finally:

File ~/.pyenv/versions/3.12.0/lib/python3.12/site-packages/IPython/lib/pretty.py:779, in _repr_pprint(obj, p, cycle)
    777 """A pprint that just redirects to the normal repr function."""
    778 # Find newlines and replace them with p.break_()
--> 779 output = repr(obj)
    780 lines = output.splitlines()
    781 with p.group():

TypeError: __repr__ returned non-string (type NoneType)
λ ~ ::

[Carreau]

Do you have any custom configuration ?

I can't reproduce so it's hard to find which object returns a None repr:

$ ipython
Python 3.12.3 | packaged by conda-forge | (main, Apr 15 2024, 18:35:20) [Clang 16.0.6 ]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.24.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: globals()
Out[1]:
{'__name__': '__main__',
 '__doc__': 'Automatically created module for IPython interactive environment',
 '__package__': None,
 '__loader__': None,
 '__spec__': None,
 '__builtin__': <module 'builtins' (built-in)>,
 '__builtins__': <module 'builtins' (built-in)>,
 '_ih': ['', 'globals()'],
 '_oh': {},
 '_dh': [PosixPath('/.../ipython')],
 'In': ['', 'globals()'],
 'Out': {},
 'get_ipython': <bound method InteractiveShell.get_ipython of <IPython.terminal.interactiveshell.TerminalInteractiveShell object at 0x105733d70>>,
 'exit': <IPython.core.autocall.ExitAutocall at 0x10582f2f0>,
 'quit': <IPython.core.autocall.ExitAutocall at 0x10582f2f0>,
 'open': <function _io.open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None)>,
 '_': '',
 '__': '',
 '___': '',
 'Module': ast.Module,
 'FunctionDef': ast.FunctionDef,
 'Pass': ast.Pass,
 'arguments': ast.arguments,
 'indent': <function textwrap.indent(text, prefix, predicate=None)>,
 'formatter': <IPython.core.formatters.PlainTextFormatter at 0x10582dfa0>,
 'repr_module': <function __main__.repr_module(module, p, cycle)>,
 'arg': <function __main__.arg(p, obj, name)>,
 'repr_FunctionDef': <function __main__.repr_FunctionDef(fun, p, cycle)>,
 'ast': <module 'ast' from '...'>,
 '_i': '',
 '_ii': '',
 '_iii': '',
 '_i1': 'globals()'}

In [2]:

[trag1c]

Yup, found the culprit—it's exit and quit, caused by my startup file:

type(exit).__repr__ = lambda self: self()

This "backports" IPython's behavior of quitting with just exit instead of exit() to the built-in REPL. I didn't realize IPython was also using this startup file 😄 And I guess I thought this was an IPython issue since the default REPL doesn't exit since it doesn't include exit nor quit in its globals().

I guess that makes this issue invalid?

[Carreau]

ok, all good then.

Yes I'm going to close as I don't think there is much actionable.

But thanks for opening the issue just in case.