是否有办法知道对象内部是否具有不可迭代的NoneType对象

Question

因此，我使用vininfo仅使用其VIN从外部DB中填充有关某些单元的信息，并使用此数据，我正在使用dict或annotate()将其转换为annotate().items()，但该脚本分解]

TypeError: cannot unpack non-iterable NoneType object

使用hasattr(obj, 'attr')尝试，但以相同的错误爆炸。无法使用for..in进行迭代，因为对象不是可迭代的TypeError: 'NoneType' object is not iterable。

我在具有相同VIN的CLI版本上试过，它吐出了相同的cannot unpack错误。

问题是我用来测试的VIN缺少一些准确的数据.transmission（但我想其他任何字段都会发生），可能是由于填写注册表时的拼写错误，所以我我试图忽略此字段，但我不能，因为它不存在！

VIN是：1NKZXPEX4GJ109010

回溯如下：

Traceback (most recent call last):
  File "c:\program files\python37\lib\runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "c:\program files\python37\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Program Files\Python37\Scripts\vininfo.exe\__main__.py", line 7, in <module>
  File "c:\program files\python37\lib\site-packages\vininfo\cli.py", line 51, in main
    entry_point(obj={})
  File "c:\program files\python37\lib\site-packages\click\core.py", line 764, in __call__
    return self.main(*args, **kwargs)
  File "c:\program files\python37\lib\site-packages\click\core.py", line 717, in main
    rv = self.invoke(ctx)
  File "c:\program files\python37\lib\site-packages\click\core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "c:\program files\python37\lib\site-packages\click\core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "c:\program files\python37\lib\site-packages\click\core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "c:\program files\python37\lib\site-packages\vininfo\cli.py", line 35, in show
    out(details)
  File "c:\program files\python37\lib\site-packages\vininfo\cli.py", line 24, in out
    for k, v in annotatable.annotate().items():
  File "c:\program files\python37\lib\site-packages\vininfo\common.py", line 17, in annotate
    value = getattr(self, attr_name, no_attr)
  File "c:\program files\python37\lib\site-packages\vininfo\details\_base.py", line 53, in __get__
    return DetailWrapper(instance, self)
  File "c:\program files\python37\lib\site-packages\vininfo\details\_base.py", line 20, in __init__
    attr_name, attr_idx = detail.source
TypeError: cannot unpack non-iterable NoneType object

Answer 1

您可以强制传输到空白列表：

>>> vin = vininfo.Vin("1NKZXPEX4GJ109010")
>>> vin.details.transmission = []
>>> vin.details.annotate()
OrderedDict([('Body', 'E'), ('Engine', 'Z'), ('Model', 'X'), ('Plant', 'J'), ('Serial', '109010'), ('Transmission', '')])