Re: [IronPython] Question about serialization
Thanks for the suggestion, unfortunately, again, no dice. It seems there is no way to serialize an IP object that derives from a .NET base class. Even though the base class is marked as serializable, I still get an error about the derived class not being marked as serializable when I use the fepy pickle. I'd be interested to trying using the DLR hosting mechanism...does anybody know of any docs about upgrading from IP 1.x to IP 2 script hosting? Thanks, Paul Sanghyeon Seo wrote: 2008/3/26, Paul Turbett [EMAIL PROTECTED]: It seems that whilst serializing .NET classes is trivial, and serializing python classes is trivial, serializing something that touches both is proving quite difficult. Any further suggestions gratefully received! I suggest using copy_reg to register .NET class to Python pickle mechanism. See: http://docs.python.org/lib/module-copyreg.html I actually implemented this back in the last year. http://lists.ironpython.com/pipermail/users-ironpython.com/2007-February/004509.html http://fepy.svn.sourceforge.net/svnroot/fepy/trunk/fepy/pickle.py ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
Re: [IronPython] Question about serialization
Unfortunately I don't think what you want will work. If it's your .NET class you could implement __reduce_ex__ and I think we'd pick it up and use that for the serialization. But if it's some arbitrary framework class then you'll run into trouble. On IronPython 2.0 you could have an extension class w/ the __reduce_ex__ function, have an ExtensionTypeAttribute that links the .NET base class and the extension class, and then call RuntimeHelpers.RegisterAssembly and we'd pick up the extension method. Also, we do have a feature request for this on CodePlex: http://www.codeplex.com/IronPython/WorkItem/View.aspx?WorkItemId=13401 Voting on it would raise its priority and we'd be more likely to do it sooner rather than later. From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Turbett Sent: Wednesday, March 26, 2008 4:56 AM To: Discussion of IronPython Subject: Re: [IronPython] Question about serialization Thanks Michael for the advice. Must appreciated. Unfortunately I hasn't worked out yet tho :( I can use pickle from C# using Evaluate, or from within a Python class, on a pure Python object. However any attempt at pickling a python object that derives from a C# base result in an exception like this: Cannot convert MyObject(MyObject object at 0x002B) to Int32 Exploring further, I came across Ops.GetDynamicType() and Ops.GetAttrsNames() which I thought might be helpful to get the attributes of an object and serialize it somehow (manually), but GetAttrNames requires an ICallerContext, and I can't see how to get one of those. It seems that whilst serializing .NET classes is trivial, and serializing python classes is trivial, serializing something that touches both is proving quite difficult. Any further suggestions gratefully received! Thanks, Paul Michael Foord wrote: Paul Turbett wrote: Hi, I'm using IP as a scripting engine in a C# app. I have various Python classes that derive from a C# base class, and have there own additional data functionality. I would like to be able to serialize instances of the Python classes from the C# host for persistence across sessions. Using the standard BinaryFormatter with the Serializable attribute is not working - I get an error about the python class not being marked as serializable (the C# base class is marked as serializable though). How can I serialize python objects from C#? Should I use reflection to roll my own serializer, or is there something in one of the lesser documented assemblies like Ops I should use? Typically for serializing Python objects you would use pickle [1]. The 'dumps' function returns a string (make sure you use the text protocol for IronPython). You could then execute code inside the Python engine to serialize / deserialize objects. I've not tried this for instances that inherit from C# base classes - but it should work fine. :-) Michael Foord http://www.ironpythoninaction.com .. [1] http://docs.python.org/lib/module-pickle.html I'm using IP 1.1.1 (but will move to 2.0 if that will help). Any pointers advice greatly appreciated! Thanks, Paul ___ Users mailing list Users@lists.ironpython.commailto:Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com ___ Users mailing list Users@lists.ironpython.commailto:Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
Re: [IronPython] Question about serialization
Ooh, I was unaware of __reduce__ and __reduce_ex__; thanks. On Wed, Mar 26, 2008 at 8:36 AM, Dino Viehland [EMAIL PROTECTED] wrote: Unfortunately I don't think what you want will work. If it's your .NET class you could implement __reduce_ex__ and I think we'd pick it up and use that for the serialization. But if it's some arbitrary framework class then you'll run into trouble. On IronPython 2.0 you could have an extension class w/ the __reduce_ex__ function, have an ExtensionTypeAttribute that links the .NET base class and the extension class, and then call RuntimeHelpers.RegisterAssembly and we'd pick up the extension method. Also, we do have a feature request for this on CodePlex: http://www.codeplex.com/IronPython/WorkItem/View.aspx?WorkItemId=13401 Voting on it would raise its priority and we'd be more likely to do it sooner rather than later. *From:* [EMAIL PROTECTED] [mailto: [EMAIL PROTECTED] *On Behalf Of *Paul Turbett *Sent:* Wednesday, March 26, 2008 4:56 AM *To:* Discussion of IronPython *Subject:* Re: [IronPython] Question about serialization Thanks Michael for the advice. Must appreciated. Unfortunately I hasn't worked out yet tho :( I can use pickle from C# using Evaluate, or from within a Python class, on a pure Python object. However any attempt at pickling a python object that derives from a C# base result in an exception like this: Cannot convert MyObject(MyObject object at 0x002B) to Int32 Exploring further, I came across Ops.GetDynamicType() and Ops.GetAttrsNames() which I thought might be helpful to get the attributes of an object and serialize it somehow (manually), but GetAttrNames requires an ICallerContext, and I can't see how to get one of those. It seems that whilst serializing .NET classes is trivial, and serializing python classes is trivial, serializing something that touches both is proving quite difficult. Any further suggestions gratefully received! Thanks, Paul Michael Foord wrote: Paul Turbett wrote: Hi, I'm using IP as a scripting engine in a C# app. I have various Python classes that derive from a C# base class, and have there own additional data functionality. I would like to be able to serialize instances of the Python classes from the C# host for persistence across sessions. Using the standard BinaryFormatter with the Serializable attribute is not working - I get an error about the python class not being marked as serializable (the C# base class is marked as serializable though). How can I serialize python objects from C#? Should I use reflection to roll my own serializer, or is there something in one of the lesser documented assemblies like Ops I should use? Typically for serializing Python objects you would use pickle [1]. The 'dumps' function returns a string (make sure you use the text protocol for IronPython). You could then execute code inside the Python engine to serialize / deserialize objects. I've not tried this for instances that inherit from C# base classes - but it should work fine. :-) Michael Foord http://www.ironpythoninaction.com .. [1] http://docs.python.org/lib/module-pickle.html I'm using IP 1.1.1 (but will move to 2.0 if that will help). Any pointers advice greatly appreciated! Thanks, Paul ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
Re: [IronPython] Question about serialization
I was thinking that Python's lack of a global namespace for classes would be a problem -- but of course it's not because you'd actually be looking in the CLR namespace. So you could just fail the deserialize if the CLR base class doesn't already exist. It would still be nice to be able to auto-load an assembly when the base class is strongly-named. On Wed, Mar 26, 2008 at 8:42 AM, Dino Viehland [EMAIL PROTECTED] wrote: My guess is you'd restrict it only to .NET objects which are marked as being serializable. Then you'd ask the object to serialize it's self and then stuff that into the pickle stream along w/ the extra Python info. That's probably include a type name which you'd just load and see what you got – much like how cPickle does an import and uses what it gets when it's loading a global. *From:* [EMAIL PROTECTED] [mailto: [EMAIL PROTECTED] *On Behalf Of *Curt Hagenlocher *Sent:* Wednesday, March 26, 2008 8:31 AM *To:* Discussion of IronPython *Subject:* Re: [IronPython] Question about serialization This is an interesting problem. Python's pickle writes out enough data to rebuild the object entirely -- including the class definition, if the object is a user-defined type. How do you accurately write out a class definition for a C# base class? Would you restrict it to strongly named classes? On Wed, Mar 26, 2008 at 4:55 AM, Paul Turbett [EMAIL PROTECTED] wrote: Thanks Michael for the advice. Must appreciated. Unfortunately I hasn't worked out yet tho :( I can use pickle from C# using Evaluate, or from within a Python class, on a pure Python object. However any attempt at pickling a python object that derives from a C# base result in an exception like this: Cannot convert MyObject(MyObject object at 0x002B) to Int32 Exploring further, I came across Ops.GetDynamicType() and Ops.GetAttrsNames() which I thought might be helpful to get the attributes of an object and serialize it somehow (manually), but GetAttrNames requires an ICallerContext, and I can't see how to get one of those. It seems that whilst serializing .NET classes is trivial, and serializing python classes is trivial, serializing something that touches both is proving quite difficult. Any further suggestions gratefully received! Thanks, Paul Michael Foord wrote: Paul Turbett wrote: Hi, I'm using IP as a scripting engine in a C# app. I have various Python classes that derive from a C# base class, and have there own additional data functionality. I would like to be able to serialize instances of the Python classes from the C# host for persistence across sessions. Using the standard BinaryFormatter with the Serializable attribute is not working - I get an error about the python class not being marked as serializable (the C# base class is marked as serializable though). How can I serialize python objects from C#? Should I use reflection to roll my own serializer, or is there something in one of the lesser documented assemblies like Ops I should use? Typically for serializing Python objects you would use pickle [1]. The 'dumps' function returns a string (make sure you use the text protocol for IronPython). You could then execute code inside the Python engine to serialize / deserialize objects. I've not tried this for instances that inherit from C# base classes - but it should work fine. :-) Michael Foord http://www.ironpythoninaction.com .. [1] http://docs.python.org/lib/module-pickle.html I'm using IP 1.1.1 (but will move to 2.0 if that will help). Any pointers advice greatly appreciated! Thanks, Paul ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
Re: [IronPython] Question about serialization
2008/3/26, Paul Turbett [EMAIL PROTECTED]: It seems that whilst serializing .NET classes is trivial, and serializing python classes is trivial, serializing something that touches both is proving quite difficult. Any further suggestions gratefully received! I suggest using copy_reg to register .NET class to Python pickle mechanism. See: http://docs.python.org/lib/module-copyreg.html I actually implemented this back in the last year. http://lists.ironpython.com/pipermail/users-ironpython.com/2007-February/004509.html http://fepy.svn.sourceforge.net/svnroot/fepy/trunk/fepy/pickle.py -- Seo Sanghyeon ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
[IronPython] Question about serialization
Hi, I'm using IP as a scripting engine in a C# app. I have various Python classes that derive from a C# base class, and have there own additional data functionality. I would like to be able to serialize instances of the Python classes from the C# host for persistence across sessions. Using the standard BinaryFormatter with the Serializable attribute is not working - I get an error about the python class not being marked as serializable (the C# base class is marked as serializable though). How can I serialize python objects from C#? Should I use reflection to roll my own serializer, or is there something in one of the lesser documented assemblies like Ops I should use? I'm using IP 1.1.1 (but will move to 2.0 if that will help). Any pointers advice greatly appreciated! Thanks, Paul ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
Re: [IronPython] Question about serialization
Paul Turbett wrote: Hi, I'm using IP as a scripting engine in a C# app. I have various Python classes that derive from a C# base class, and have there own additional data functionality. I would like to be able to serialize instances of the Python classes from the C# host for persistence across sessions. Using the standard BinaryFormatter with the Serializable attribute is not working - I get an error about the python class not being marked as serializable (the C# base class is marked as serializable though). How can I serialize python objects from C#? Should I use reflection to roll my own serializer, or is there something in one of the lesser documented assemblies like Ops I should use? Typically for serializing Python objects you would use pickle [1]. The 'dumps' function returns a string (make sure you use the text protocol for IronPython). You could then execute code inside the Python engine to serialize / deserialize objects. I've not tried this for instances that inherit from C# base classes - but it should work fine. :-) Michael Foord http://www.ironpythoninaction.com .. [1] http://docs.python.org/lib/module-pickle.html I'm using IP 1.1.1 (but will move to 2.0 if that will help). Any pointers advice greatly appreciated! Thanks, Paul ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com ___ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
