python - 为什么我从mongoalchemy获得ExtraValueException？

这是我的课：

class Presentation(db.Document):
    title = db.StringField(max_length=120, required=True)
    author = db.StringField (required=True)
    pages = db.DocumentField(Page, required=False)
    tags = db.StringField(max_length=120, required=False)
    id = db.IntField(required=True)
    currentPage = db.IntField()
def __str__(self):
     return 'Title:%s author:%s  id:%d currentPage:%d' % ( self.title, self.author,self.id,self.currentPage)

当我从Mongo Shell中使用它时，一切看起来都很好：
db.presentation.find（{id:2}）

{ "_id" : ObjectId("4e9cdddd0ad5c97ee6000000"),
"author" : "admin", "currentPage" : 3, "id" : 2,
"pages" : { "content" : "", "pagenum" : 0 }, "title" : "dd" }

但当我使用Mongoalchemy时，
p=query.filter（presentation.id==2）.first（）

Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "build/bdist.macosx-10.7-intel/egg/mongoalchemy/query.py", line 136, in first
File "build/bdist.macosx-10.7-intel/egg/mongoalchemy/query.py", line 388, in next
File "build/bdist.macosx-10.7-intel/egg/mongoalchemy/document.py", line 318, in unwrap
File "build/bdist.macosx-10.7-intel/egg/mongoalchemy/document.py", line 152, in __init__

mongoalchemy.exceptions.ExtraValueException: currentPage

最佳答案

我阅读了doc string of the exception并且似乎对于mongoalchemy，定义的模型没有将currentpage注册为Presentation文档的属性，但是在复制粘贴的代码中，类定义定义定义了该属性。
如果复制粘贴的类是在项目中定义的类，请尝试删除项目中的.pyc文件并重新运行应用程序。
顺便说一下，currentPage变量名不遵循PEP8命名约定。