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Change in behaviour Python 3.7 > 3.8

Does anyone know of a service where I can send my STL files and have them converted to .x3g file, so I can simply upload the file to my SD card and run the parts in my Printer (Creator Pro Flashforge).
I have had no success in doing this and converting to the G-code required for my machine...


Bill O.

-----Original Message-----
From: Python-list < at> On Behalf Of Souvik Dutta
Sent: Thursday, February 6, 2020 8:48 AM
To: Frank Millman <frank at>
Cc: python-list at
Subject: Re: Change in behaviour Python 3.7 > 3.8

You might find this helpful.

Thank you ??

On Thu, Feb 6, 2020, 6:29 PM Frank Millman <frank at> wrote:

> Hi all
> I have noticed a change in behaviour in Python 3.8 compared with 
> previous versions of Python going back to at least 2.7. I am pretty 
> sure that it is not a problem, and is caused by my relying on a 
> certain sequence of events at shutdown, which of course is not guaranteed.
> However, any change in behaviour is worth reporting, just in case it 
> was unintended, so I thought I would mention it here.
> I have a module (A) containing common objects shared by other modules. 
> I have a module (B) which imports one of these common objects - a set().
> Module B defines a Class, and creates a global instance of this class 
> when the module is created. This instance is never explicitly deleted, 
> so I assume it gets implicitly deleted at shutdown. It has a __del__() 
> method (only for temporary debugging purposes, so will be removed for
> production) and the __del__ method uses the set() object imported from 
> Module A.
> This has worked for years, but now when the __del__ method is called, 
> the common object, which was a set(), has become None.
> My assumption is that Module A gets cleaned up before Module B, and 
> when Module B tries to access the common set() object it no longer exists.
> I have a workaround, so I am just reporting this for the record.
> Frank Millman
> --