Re: [sqlalchemy] How to get `func` attribute from hybrid_method
вторник, 14 марта 2017 г., 17:15:25 UTC+3 пользователь Mike Bayer написал:
>
>
>
> On 03/14/2017 10:02 AM, Антонио Антуан wrote:
> > Hi.
> > I use sqlalchemy 1.0.17, thanks for you great library :)
> >
> > I have such code:
> > |
> >
> >
> > classFlagsMixin(object):
> > @hybrid_method
> > defexist_flag(self,flag):
> > ifnotself.flags ornotflag:
> > returnFalse
> > returnself.flags ==flag
> >
> > @exist_flag.expression
> > defexist_flag(self,flag):
> > returnand_(flag !=0,self.flags !=0,self.flags.op('&')(flag)!=0)
> >
> >
> > classSomeModel(Base,FlagsMixin,AnyOtherClass):
> > # class attrs and methods
> >
> > |
> >
> >
> > In case of optimization, I want to create sqlalchemy-free class,
>
> what sort of optimization? are you having a performance problem?
>
Just hardcode optimization, no preformance problems, don't worry :)
>
>
> which
> > contains all methods and attributes of class. So, i wrote that code:
> >
> > |
> >
> >
> > @staticmethod
> > def_get_sa_free_class(klass,with_mro=False):
> > sa_free_cls =getattr(klass,'__sa_free_cls',None)
> >
> > ifsa_free_cls isNone:
> > items ={}
> > klasses =[klass]ifnotwith_mro elseklass.__mro__
> > fork inklasses:
> > forname,val ink.__dict__.items():
> > ifname notinitems andname
> >
> notin['__mapper__','__dict__','__class__','_sa_class_manager','query','metadata']:
>
>
> > ifisinstance(val,InstrumentedAttribute):
> > items[name]=None
> > else:
> > items[name]=val
> > formethod_name in('exist_flag',):
> > items[method_name]=getattr(klass,method_name)
> > sa_free_cls
> =type('Unbound'+klass.__name__,(object,),dict(items))
> > sa_free_cls._sa_free =True
> >
> > sa_free_cls.__init__
> =klass._sa_class_manager.original_init.im_func
> >
> > setattr(klass,'__sa_free_cls',sa_free_cls)
> > returnsa_free_cls
>
> So what you're trying to do is: 1. create a class 2. map it 3. then
> extract it into something unmapped. this seems backwards. Why not
> create your class as "unmapped", then make a subclass of it that is
> mapped?
>
>
> class MyOptimizedClass(FlagsMixin):
> # stuff
>
>
> class MyMappedClass(MyOptimizedClass, Base):
> __tablename__ = ...
>
> # stuff
>
>
> Or something like that, where you make use of your descriptor
> declaration directly instead of reverse engineering it.
>
> > Result class should has `exist_flag()` method, and it has to be used
> > always with `func` attribute of hybrid_property, neither `expr` (as I
> > want to have SQLA-free class).
> >
> > As you can see, I want to ensure `exist_flag()` method existence in
> > result `klass` object, and if method called with `with_mro=False`.
> > But, of course, such a way can't allow this, because of descriptor logic
> > - return `expr` if instance not specified:
> >
> > |
> > klass.exist_flag(1)
> >
> >
> > |
> >
> > Also, I tried to use this versions with same result -
> AttributeError(''):
> >
> >
> > |
> > klass.exist_flag.func
> > klass.exist_flag.__class__.func
>
> well when you access the hybrid like that it gets invoked. you'd need
> to get it either as:
>
> hybrid = klass.__class__.__dict__['exist_flag']
>
> >>> getattr(klass, 'exist_flag')
>
>>>
>>> klass.__class__.__dict__['exist_flag']
Traceback (most recent call last):
File "", line 1, in
KeyError: 'exist_flag'
> or
>
> from sqlalchemy import inspect
> mapper = inspect(klass)
> hybrid = mapper.all_orm_descriptors.exist_flag
>
>
> you probably want to be using mapper.all_orm_descriptors to help with
> your inspection.
>
Yes, it helps, thank you :)
>
> > ...
> >
> > AttributeError: 'function' object has no attribute 'func'
> >
> > |
> >
> > Is there any way to get `func` attribute of hybrid_method?
> > And also, maybe sqlalchemy already has some alternative to get
> > sqla-free-class?
> >
> > Thank you again.
> > Anton.
> >
> > --
> > 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
> > .
> > To post to this group, send email to sqlal...@googlegroups.com
>
> > .
> > Visit this group at https://groups.google.com/group/sqlalchemy.
> > For more options, visit
Re: [sqlalchemy] How to get `func` attribute from hybrid_method
On 03/14/2017 10:02 AM, Антонио Антуан wrote:
Hi.
I use sqlalchemy 1.0.17, thanks for you great library :)
I have such code:
|
classFlagsMixin(object):
@hybrid_method
defexist_flag(self,flag):
ifnotself.flags ornotflag:
returnFalse
returnself.flags ==flag
@exist_flag.expression
defexist_flag(self,flag):
returnand_(flag !=0,self.flags !=0,self.flags.op('&')(flag)!=0)
classSomeModel(Base,FlagsMixin,AnyOtherClass):
# class attrs and methods
|
In case of optimization, I want to create sqlalchemy-free class,
what sort of optimization? are you having a performance problem?
which
contains all methods and attributes of class. So, i wrote that code:
|
@staticmethod
def_get_sa_free_class(klass,with_mro=False):
sa_free_cls =getattr(klass,'__sa_free_cls',None)
ifsa_free_cls isNone:
items ={}
klasses =[klass]ifnotwith_mro elseklass.__mro__
fork inklasses:
forname,val ink.__dict__.items():
ifname notinitems andname
notin['__mapper__','__dict__','__class__','_sa_class_manager','query','metadata']:
ifisinstance(val,InstrumentedAttribute):
items[name]=None
else:
items[name]=val
formethod_name in('exist_flag',):
items[method_name]=getattr(klass,method_name)
sa_free_cls =type('Unbound'+klass.__name__,(object,),dict(items))
sa_free_cls._sa_free =True
sa_free_cls.__init__ =klass._sa_class_manager.original_init.im_func
setattr(klass,'__sa_free_cls',sa_free_cls)
returnsa_free_cls
So what you're trying to do is: 1. create a class 2. map it 3. then
extract it into something unmapped. this seems backwards. Why not
create your class as "unmapped", then make a subclass of it that is mapped?
class MyOptimizedClass(FlagsMixin):
# stuff
class MyMappedClass(MyOptimizedClass, Base):
__tablename__ = ...
# stuff
Or something like that, where you make use of your descriptor
declaration directly instead of reverse engineering it.
Result class should has `exist_flag()` method, and it has to be used
always with `func` attribute of hybrid_property, neither `expr` (as I
want to have SQLA-free class).
As you can see, I want to ensure `exist_flag()` method existence in
result `klass` object, and if method called with `with_mro=False`.
But, of course, such a way can't allow this, because of descriptor logic
- return `expr` if instance not specified:
|
klass.exist_flag(1)
|
Also, I tried to use this versions with same result - AttributeError(''):
|
klass.exist_flag.func
klass.exist_flag.__class__.func
well when you access the hybrid like that it gets invoked. you'd need
to get it either as:
hybrid = klass.__class__.__dict__['exist_flag']
or
from sqlalchemy import inspect
mapper = inspect(klass)
hybrid = mapper.all_orm_descriptors.exist_flag
you probably want to be using mapper.all_orm_descriptors to help with
your inspection.
...
AttributeError: 'function' object has no attribute 'func'
|
Is there any way to get `func` attribute of hybrid_method?
And also, maybe sqlalchemy already has some alternative to get
sqla-free-class?
Thank you again.
Anton.
--
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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.
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.
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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] How to get `func` attribute from hybrid_method
Hi.
I use sqlalchemy 1.0.17, thanks for you great library :)
I have such code:
class FlagsMixin(object):
@hybrid_method
def exist_flag(self, flag):
if not self.flags or not flag:
return False
return self.flags & flag == flag
@exist_flag.expression
def exist_flag(self, flag):
return and_(flag != 0, self.flags != 0, self.flags.op('&')(flag) != 0)
class SomeModel(Base, FlagsMixin, AnyOtherClass):
# class attrs and methods
In case of optimization, I want to create sqlalchemy-free class, which
contains all methods and attributes of class. So, i wrote that code:
@staticmethod
def _get_sa_free_class(klass, with_mro=False):
sa_free_cls = getattr(klass, '__sa_free_cls', None)
if sa_free_cls is None:
items = {}
klasses = [klass] if not with_mro else klass.__mro__
for k in klasses:
for name, val in k.__dict__.items():
if name not in items and name not in ['__mapper__', '__dict__',
'__class__', '_sa_class_manager', 'query', 'metadata']:
if isinstance(val, InstrumentedAttribute):
items[name] = None
else:
items[name] = val
for method_name in ('exist_flag', ):
items[method_name] = getattr(klass, method_name)
sa_free_cls = type('Unbound' + klass.__name__, (object, ), dict(items))
sa_free_cls._sa_free = True
sa_free_cls.__init__ = klass._sa_class_manager.original_init.im_func
setattr(klass, '__sa_free_cls', sa_free_cls)
return sa_free_cls
Result class should has `exist_flag()` method, and it has to be used always
with `func` attribute of hybrid_property, neither `expr` (as I want to have
SQLA-free class).
As you can see, I want to ensure `exist_flag()` method existence in result
`klass` object, and if method called with `with_mro=False`.
But, of course, such a way can't allow this, because of descriptor logic -
return `expr` if instance not specified:
klass.exist_flag(1)
Also, I tried to use this versions with same result - AttributeError(''):
klass.exist_flag.func
klass.exist_flag.__class__.func
...
AttributeError: 'function' object has no attribute 'func'
Is there any way to get `func` attribute of hybrid_method?
And also, maybe sqlalchemy already has some alternative to get
sqla-free-class?
Thank you again.
Anton.
--
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+unsubscr...@googlegroups.com.
To post to this group, send email to sqlalchemy@googlegroups.com.
Visit this group at https://groups.google.com/group/sqlalchemy.
For more options, visit https://groups.google.com/d/optout.
