Re: [sqlalchemy] Re: Duplicate `self`, without affecting the original instance in memory…
Then I'm not understanding the question, or at least why make_transient is
not working for you. make_transient just sets the state of the existing
object to be a new row, essentially. No new self is created (unless I am
seriously forgetting how it works, don't have the code in front of me)
which seems like what you are asking for.
On Sat, Jun 23, 2018, 6:03 AM Dave von Umlaut wrote:
> I don't mind using merge()… My problem is that using the code linked
> above, I cannot seem to make it to keep the original `self` (it invariably
> gets replaced by the new persisted object).
>
> I'm happy with a shallow copy of the object (I handle the relationship
> separately). My next plan is literally to duplicate the DB row…
>
> On Saturday, 23 June 2018 02:35:39 UTC+9, Mike Bayer wrote:
>>
>> There's no shortcut outside of merge () for copying attributes, copies
>> are hard to generalize so you probably want to put copy constructors on
>> your classes if you need to do that often.
>>
>> On Fri, Jun 22, 2018, 1:24 PM Jonathan Vanasco
>> wrote:
>>
>>>
>>> FWIW, i use these methods in my base class to copy the object into a
>>> dict.
>>>
>>>
>>> def columns_as_dict(self):
>>> """
>>> Beware: this function will trigger a load of attributes if they
>>> have not been loaded yet.
>>> """
>>> return dict((col.name, getattr(self, col.name))
>>> for col
>>> in sqlalchemy.orm.class_mapper(self.__class__).
>>> mapped_table.c
>>> )
>>>
>>>
>>> def loaded_columns_as_dict(self):
>>> """
>>> This function will only return the loaded columns as a dict.
>>> """
>>> _dict = self.__dict__
>>> return {col.name: _dict[col.name]
>>> for col in sqlalchemy.orm.class_mapper(self.__class__).
>>> mapped_table.c
>>> if col.name in _dict
>>> }
>>>
>>>
>>>
>>> --
>>> SQLAlchemy -
>>> The Python SQL Toolkit and Object Relational Mapper
>>>
>>> http://www.sqlalchemy.org/
>>>
>>> To post example code, please provide an MCVE: Minimal, Complete, and
>>> Verifiable Example. See http://stackoverflow.com/help/mcve for a full
>>> description.
>>> ---
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>>> Groups "sqlalchemy" group.
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>>>
>> --
> SQLAlchemy -
> The Python SQL Toolkit and Object Relational Mapper
>
> http://www.sqlalchemy.org/
>
> To post example code, please provide an MCVE: Minimal, Complete, and
> Verifiable Example. See http://stackoverflow.com/help/mcve for a full
> description.
> ---
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>
--
SQLAlchemy -
The Python SQL Toolkit and Object Relational Mapper
http://www.sqlalchemy.org/
To post example code, please provide an MCVE: Minimal, Complete, and Verifiable
Example. See http://stackoverflow.com/help/mcve for a full description.
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Re: [sqlalchemy] Re: Duplicate `self`, without affecting the original instance in memory…
I don't mind using merge()… My problem is that using the code linked above,
I cannot seem to make it to keep the original `self` (it invariably gets
replaced by the new persisted object).
I'm happy with a shallow copy of the object (I handle the relationship
separately). My next plan is literally to duplicate the DB row…
On Saturday, 23 June 2018 02:35:39 UTC+9, Mike Bayer wrote:
>
> There's no shortcut outside of merge () for copying attributes, copies are
> hard to generalize so you probably want to put copy constructors on your
> classes if you need to do that often.
>
> On Fri, Jun 22, 2018, 1:24 PM Jonathan Vanasco > wrote:
>
>>
>> FWIW, i use these methods in my base class to copy the object into a
>> dict.
>>
>>
>> def columns_as_dict(self):
>> """
>> Beware: this function will trigger a load of attributes if they
>> have not been loaded yet.
>> """
>> return dict((col.name, getattr(self, col.name))
>> for col
>> in sqlalchemy.orm.class_mapper(self.__class__).
>> mapped_table.c
>> )
>>
>>
>> def loaded_columns_as_dict(self):
>> """
>> This function will only return the loaded columns as a dict.
>> """
>> _dict = self.__dict__
>> return {col.name: _dict[col.name]
>> for col in sqlalchemy.orm.class_mapper(self.__class__).
>> mapped_table.c
>> if col.name in _dict
>> }
>>
>>
>>
>> --
>> SQLAlchemy -
>> The Python SQL Toolkit and Object Relational Mapper
>>
>> http://www.sqlalchemy.org/
>>
>> To post example code, please provide an MCVE: Minimal, Complete, and
>> Verifiable Example. See http://stackoverflow.com/help/mcve for a full
>> description.
>> ---
>> You received this message because you are subscribed to the Google Groups
>> "sqlalchemy" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to sqlalchemy+...@googlegroups.com .
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>> .
>> Visit this group at https://groups.google.com/group/sqlalchemy.
>> For more options, visit https://groups.google.com/d/optout.
>>
>
--
SQLAlchemy -
The Python SQL Toolkit and Object Relational Mapper
http://www.sqlalchemy.org/
To post example code, please provide an MCVE: Minimal, Complete, and Verifiable
Example. See http://stackoverflow.com/help/mcve for a full description.
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Re: [sqlalchemy] Re: Duplicate `self`, without affecting the original instance in memory…
There's no shortcut outside of merge () for copying attributes, copies are
hard to generalize so you probably want to put copy constructors on your
classes if you need to do that often.
On Fri, Jun 22, 2018, 1:24 PM Jonathan Vanasco
wrote:
>
> FWIW, i use these methods in my base class to copy the object into a
> dict.
>
>
> def columns_as_dict(self):
> """
> Beware: this function will trigger a load of attributes if they
> have not been loaded yet.
> """
> return dict((col.name, getattr(self, col.name))
> for col
> in sqlalchemy.orm.class_mapper(self.__class__).
> mapped_table.c
> )
>
>
> def loaded_columns_as_dict(self):
> """
> This function will only return the loaded columns as a dict.
> """
> _dict = self.__dict__
> return {col.name: _dict[col.name]
> for col in sqlalchemy.orm.class_mapper(self.__class__).
> mapped_table.c
> if col.name in _dict
> }
>
>
>
> --
> SQLAlchemy -
> The Python SQL Toolkit and Object Relational Mapper
>
> http://www.sqlalchemy.org/
>
> To post example code, please provide an MCVE: Minimal, Complete, and
> Verifiable Example. See http://stackoverflow.com/help/mcve for a full
> description.
> ---
> You received this message because you are subscribed to the Google Groups
> "sqlalchemy" group.
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> email to sqlalchemy+unsubscr...@googlegroups.com.
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> Visit this group at https://groups.google.com/group/sqlalchemy.
> For more options, visit https://groups.google.com/d/optout.
>
--
SQLAlchemy -
The Python SQL Toolkit and Object Relational Mapper
http://www.sqlalchemy.org/
To post example code, please provide an MCVE: Minimal, Complete, and Verifiable
Example. See http://stackoverflow.com/help/mcve for a full description.
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[sqlalchemy] Re: Duplicate `self`, without affecting the original instance in memory…
FWIW, i use these methods in my base class to copy the object into a dict.
def columns_as_dict(self):
"""
Beware: this function will trigger a load of attributes if they
have not been loaded yet.
"""
return dict((col.name, getattr(self, col.name))
for col
in sqlalchemy.orm.class_mapper(self.__class__).
mapped_table.c
)
def loaded_columns_as_dict(self):
"""
This function will only return the loaded columns as a dict.
"""
_dict = self.__dict__
return {col.name: _dict[col.name]
for col in sqlalchemy.orm.class_mapper(self.__class__).
mapped_table.c
if col.name in _dict
}
--
SQLAlchemy -
The Python SQL Toolkit and Object Relational Mapper
http://www.sqlalchemy.org/
To post example code, please provide an MCVE: Minimal, Complete, and Verifiable
Example. See http://stackoverflow.com/help/mcve for a full description.
---
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