Running pydantic type validation in generated code string raises KeyError: '__name__'

[KhoomeiK]

Initial Checks

• I confirm that I'm using Pydantic V2

Description

When running type validation of non-pydantic_validator objects in a string execution (e.g. generated code) context, a KeyError: '__name__' is raised by TypeAdapter.__init__ unless {'__name__': '__main__'} is passed as part of global variables to exec.

While this issue is trivial to fix for a user if they understand the execution context requirements, it seems this __name__ requirement was only recently added to the type adapter and the raised error is fairly confusing and/or unexpected behavior.

Traceback (most recent call last):
  File "python3.11/site-packages/pydantic/type_adapter.py", line 197, in __init__
    validator = _getattr_no_parents(type, '__pydantic_validator__')
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "python3.11/site-packages/pydantic/type_adapter.py", line 98, in _getattr_no_parents
    raise AttributeError(attribute)
AttributeError: __pydantic_validator__

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 2, in <module>
  File "python3.11/site-packages/pydantic/type_adapter.py", line 201, in __init__
    module = cast(str, f.f_globals['__name__'])
                       ~~~~~~~~~~~^^^^^^^^^^^^
KeyError: '__name__'

The simplest fix here in my mind is to check if __name__ is present on f.f_globals and if not, either raise a more informative error or set it to __main__ by default.

Example Code

code = """import pydantic
pydantic.TypeAdapter(str).validate_python('foo')"""

exec(code, {"bar": "baz"})

# USER FIX:
exec(code, {"bar": "baz", '__name__': '__main__'})

Python, Pydantic & OS Version

pydantic version: 2.5.2
        pydantic-core version: 2.14.5
          pydantic-core build: profile=release pgo=true
                 install path: /Users/rohan/Library/Caches/pypoetry/virtualenvs/deworker-TwLL-mi8-py3.11/lib/python3.11/site-packages/pydantic
               python version: 3.11.6 (main, Nov  2 2023, 04:39:43) [Clang 14.0.3 (clang-1403.0.22.14.1)]
                     platform: macOS-13.3-arm64-arm-64bit
             related packages: typing_extensions-4.9.0 mypy-1.7.1 pydantic-settings-2.1.0

[hramezani]

Thanks @KhoomeiK for reporting this.

It can be fix by passing module to TypeAdapter.

pydantic.TypeAdapter(str, module='my_module').validate_python('foo')

BTW, I've created #8470 for fixing the bug