473,597 Members | 2,149 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

Re: When do I get "multiple bases have instance lay-out conflict"error?

On Mon, Sep 15, 2008 at 6:06 AM, Harish K Vishwanath
<ha************ @gmail.comwrote :
Hello all,

When do we actually see the error :

TypeError: Error when calling the metaclass bases
multiple bases have instance lay-out conflict
I searched the web and I could not find a correct guideline as to when such
an error could arise. One of the places said that "A new style class cannot
inherit from more than one python built-in class". That is.,
>>>class A(dict,list):
... pass
wouldn't work.
"built-in type" generally means "implemente d in C", also sometimes
called "extension type".
>>>class A(Exception,per sistent.Persist ent):
... pass
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: Error when calling the metaclass bases
multiple bases have instance lay-out conflict

Still declaration of class A fails. Any idea? What is the exact rule when
python throws up " multiple bases have instance lay-out conflict" error?
Both the Exception and ZODB Persistent objects are implemented in C,
and they have different ideas for the format of the struct that holds
an object's data. It can be tricky to tell by introspection whether a
new-style class is implemented in Python or C. One possible
>>class Foo(object): pass
>>'__module__ ' in vars(Foo)
>>'__module__ ' in vars(Exception)

I'm not sure whether this is valid in all cases. Someone else may
know of a better way.

Sep 16 '08 #1
0 1712

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

by: Rolf Wester | last post by:
Hi, I have a form with a select element with multiple="true". When using the GET method (I suppose the same happens with the POST method) I can seen that the form sends channels=CH1&channels=CH2 when CH1 and CH2 have been choosen. $_GET gives me "CH2". Is there any way to get all the choosen channels elements? I would be very appreciative for any help. Thank you in anticipation. Regards
by: Ari Royce Hidayat | last post by:
Dear ALL, Is there some one ever faces this problem? And fix it? The scenario is: There's an html page that hosts a .net object (using object tag), and this page opens the second html page that also hosts a .net object (e.g. by click a hyperlink).
by: Ari Royce Hidayat | last post by:
Tx a lot for idea. I've tried it, and still get not clue what causes it. I also tried to see the log file generated by IEHost (by adding IEHostLogFile to registry) and still get not clue what causes. It seems normal instead that before loading the second page (in third row from last row) there's a text read as:
by: Pankaj Jain | last post by:
Hi All, I have a class A which is derived from ServicesComponent to participate in automatic transaction with falg Transaction.Required. Class A is exposed to client through remoting on Http channal hosting into IIS. There is a class B which is also available through remoting hosted on IIS on the same URI. B creates new of A inside a function. It succeed and able to create instance of A inside B first time. But it failes in 2nd attempt when...
by: Kenjis Kaan | last post by:
I had to run DB2 on Win2k. After installation it puts a directory under c:\DB2 and c:\DB2Log and C:\Program Files\SQLLIB Now am all confused which is instance home, db2 home etc. I had to configure tivoli inventory and its all *@#$ up because of this confusion. Can someone please clarify which is which? TIA c:\DB2>wgetrim invdh_1 RIM Host: user88 RDBMS User: user881 RDBMS Vendor: DB2
by: Mairhtin O'Feannag | last post by:
Hello, We have two machines we wish to use DPF. They are both RH ES 2.1, with DB2 8.2. I read the documentation CAREFULLY, and added the following line to my db2nodes.cfg file : 1 egret 0
by: Ravi Ambros Wallau | last post by:
Hey guys: What can I do when an "Error Creating Control" is displayed on the form (instead of the control), and a tooltip indicating the error never is displayed? Is there some log, some hidden message, some entry in registry where a log is created (or that enables a log, trace, dump or whatever)... I'm a little bit frustated with this error :-( Tks, Ravi.
by: jason | last post by:
I've seen a few posts on this issue, but no clear solutions. I have a mulitiline textbox inside a datagrid. I use TemplateColumn to define as multiline with 3 rows. I have other field types like drop downs that have no issue displaying last values in edit mode with seemingly more complicated code. when I attempt to find my textbox with
by: louie.hutzel | last post by:
This JUST started happening, I don't remember changing any code: When I click the submit button on my form, stuff is supposed to happen (which it does correctly) and a result message is posted back to the same page at the top of my form alerting the user that their request has been approved or denied. However, the end result is an error message: Error Message: Object reference not set to an instance of an object.
by: Charles Packer | last post by:
In the code example below, why does the reference to gdk_pixbuf_new_from_file in main compile okay, but in subr2 gives the error "dereferencing pointer to incomplete type"? A search through this newsgroup suggests that the error arises when the proper header files are missing, but when the header file I've got is sufficient to compile one instance of the call, but not the other, I don't know where to turn next.
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth. The Art of Business Website Design Your website is...
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
by: agi2029 | last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own.... Now, this would greatly impact the work of software developers. The idea...
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules. He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms. Adolph will...
by: conductexam | last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one. At the time of converting from word file to html my equations which are in the word document file was convert into image. Globals.ThisAddIn.Application.ActiveDocument.Select();...
by: adsilva | last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
by: muto222 | last post by:
How can i add a mobile payment intergratation into php mysql website.
by: bsmnconsultancy | last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.