AttributeError: 'sqlalchemy.cimmutabledict.immutabledict' object has no attribute 'setdefault'

这个错误通常是因为你在使用 `setdefault()` 方法时，将一个不可变的字典对象传递给了它。`setdefault()` 方法需要一个可变的字典才能正常工作。

解决方法是将不可变的字典转换为可变的字典，例如使用 `dict()` 函数，然后再调用 `setdefault()` 方法。

示例代码：

my_dict = sqlalchemy.cimmutabledict.immutabledict({'key1': 'value1', 'key2': 'value2'})
my_dict = dict(my_dict) # 转换为可变字典
my_dict.setdefault('key3', 'value3')

这样就能避免 `AttributeError: 'sqlalchemy.cimmutabledict.immutabledict' object has no attribute 'setdefault'` 错误了。

相关问题

AttributeError: module 'sqlalchemy.util.queue' has no attribute 'AsyncAdaptedQueue'

针对AttributeError: module 'sqlalchemy.util.queue' has no attribute 'AsyncAdaptedQueue'的问题，这个错误通常是由于导入的模块中没有AsyncAdaptedQueue属性引起的。解决这个问题的方法是检查导入的模块是否正确，或者检查模块中是否存在AsyncAdaptedQueue属性。如果模块中确实没有AsyncAdaptedQueue属性，那么可以考虑使用其他属性或者方法来代替。另外，也可以尝试更新模块或者重新安装模块来解决这个问题。

AttributeError: module 'sqlalchemy.sql.schema' has no attribute '_schema_getter'

This error occurs when you are trying to access a non-existent attribute in the `sqlalchemy.sql.schema` module. Specifically, you are trying to access the `_schema_getter` attribute which does not exist in the module.

To fix this error, you should review your code and make sure that you are using the correct attribute name. It's also possible that the attribute may have been removed or renamed in a recent version of SQLAlchemy. In that case, you should check the SQLAlchemy documentation to see if there is a new way to access the functionality you need.