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lostmsu opened this issue Sep 13, 2020 · 7 comments
Closed

.NET enums should not be automatically converted to Python int and back #1220

lostmsu opened this issue Sep 13, 2020 · 7 comments
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3.0.0

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@lostmsu
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lostmsu commented Sep 13, 2020

From #1179

In Python, it should be possible to refer to enum members: MyEnum.Member, and to create arbitrary enum values from int explicitly like this: MyEnum(42). But by default a number and a value of some enum should not be freely convertible to each other. E.g. this should fail:

void Method(MyEnum value) => ...;

Python:

Method(42); # <- this should be a TypeError

We can add a generic enum codec, that could be enabled on demand to restore old behavior.
@tminka
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tminka commented Jan 3, 2021

This is related to #1099

@wollmich
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I support that. This would solve a lot of problems, e.g.: https://stackoverflow.com/q/65805093/7556646.

@lostmsu lostmsu added this to the 3.0.0 milestone Jan 20, 2021
@TheCollegedude
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Is there a workaround? I tried using IPyObjectDecoder but it is marked as "obsolete". The wiki, where I found it, seems to be
outdated.

lostmsu added a commit to losttech/pythonnet that referenced this issue Feb 20, 2021
@lostmsu
reworked Enum marshaling
8e63b07 
- enums are no longer converted to and from PyLong automatically pythonnet#1220
- one can construct an instance of MyEnum from Python using MyEnum(numeric_val), e.g. MyEnum(10)
- in the above, if MyEnum does not have [Flags] and does not have value 10 defined, to create MyEnum with value 10 one must call MyEnum(10, True). Here True is an unnamed parameter, that allows unchecked conversion
- legacy behavior has been moved to a codec (EnumPyLongCodec); enums can now be encoded by codecs
lostmsu added a commit to losttech/pythonnet that referenced this issue Feb 20, 2021
@lostmsu
reworked Enum marshaling
c00ae2b 
- enums are no longer converted to and from PyLong automatically pythonnet#1220
- one can construct an instance of MyEnum from Python using MyEnum(numeric_val), e.g. MyEnum(10)
- in the above, if MyEnum does not have [Flags] and does not have value 10 defined, to create MyEnum with value 10 one must call MyEnum(10, True). Here True is an unnamed parameter, that allows unchecked conversion
- legacy behavior has been moved to a codec (EnumPyLongCodec); enums can now be encoded by codecs
@lostmsu lostmsu mentioned this issue Feb 20, 2021
Merged
2 tasks
lostmsu added a commit to losttech/pythonnet that referenced this issue Feb 20, 2021
@lostmsu
reworked Enum marshaling
429cc3b 
- enums are no longer converted to and from PyLong automatically pythonnet#1220
- one can construct an instance of MyEnum from Python using MyEnum(numeric_val), e.g. MyEnum(10)
- in the above, if MyEnum does not have [Flags] and does not have value 10 defined, to create MyEnum with value 10 one must call MyEnum(10, True). Here True is an unnamed parameter, that allows unchecked conversion
- legacy behavior has been moved to a codec (EnumPyLongCodec); enums can now be encoded by codecs
@lostmsu
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lostmsu commented Feb 20, 2021

@TheCollegedude I've just submitted a new PR for master branch to disable default conversion.

If you are planning to stay on 2.5, you can use IPyObjectDecoder. It is marked obsolete, as it might change in 3.0 (so far it has not).

lostmsu added a commit to losttech/pythonnet that referenced this issue Feb 21, 2021
@lostmsu
reworked Enum marshaling
9bff356 
- enums are no longer converted to and from PyLong automatically pythonnet#1220
- one can construct an instance of MyEnum from Python using MyEnum(numeric_val), e.g. MyEnum(10)
- in the above, if MyEnum does not have [Flags] and does not have value 10 defined, to create MyEnum with value 10 one must call MyEnum(10, True). Here True is an unnamed parameter, that allows unchecked conversion
- legacy behavior has been moved to a codec (EnumPyLongCodec); enums can now be encoded by codecs
lostmsu added a commit to losttech/pythonnet that referenced this issue Feb 21, 2021
@lostmsu
reworked Enum marshaling
48655d8 
- enums are no longer converted to and from PyLong automatically pythonnet#1220
- one can construct an instance of MyEnum from Python using MyEnum(numeric_val), e.g. MyEnum(10)
- in the above, if MyEnum does not have [Flags] and does not have value 10 defined, to create MyEnum with value 10 one must call MyEnum(10, True). Here True is an unnamed parameter, that allows unchecked conversion
- legacy behavior has been moved to a codec (EnumPyLongCodec); enums can now be encoded by codecs
- flags enums support bitwise ops via EnumOps class
lostmsu added a commit to losttech/pythonnet that referenced this issue Feb 21, 2021
@lostmsu
reworked Enum marshaling
f77b131 
- enums are no longer converted to and from PyLong automatically pythonnet#1220
- one can construct an instance of MyEnum from Python using MyEnum(numeric_val), e.g. MyEnum(10)
- in the above, if MyEnum does not have [Flags] and does not have value 10 defined, to create MyEnum with value 10 one must call MyEnum(10, True). Here True is an unnamed parameter, that allows unchecked conversion
- legacy behavior has been moved to a codec (EnumPyLongCodec); enums can now be encoded by codecs
- flags enums support bitwise ops via EnumOps class
lostmsu added a commit to losttech/pythonnet that referenced this issue Mar 30, 2021
@lostmsu
reworked Enum marshaling
5c41499 
- enums are no longer converted to and from PyLong automatically pythonnet#1220
- one can construct an instance of MyEnum from Python using MyEnum(numeric_val), e.g. MyEnum(10)
- in the above, if MyEnum does not have [Flags] and does not have value 10 defined, to create MyEnum with value 10 one must call MyEnum(10, True). Here True is an unnamed parameter, that allows unchecked conversion
- legacy behavior has been moved to a codec (EnumPyLongCodec); enums can now be encoded by codecs
- flags enums support bitwise ops via EnumOps class
lostmsu added a commit that referenced this issue Mar 30, 2021
@lostmsu
reworked Enum marshaling
6379221 
- enums are no longer converted to and from PyLong automatically #1220
- one can construct an instance of MyEnum from Python using MyEnum(numeric_val), e.g. MyEnum(10)
- in the above, if MyEnum does not have [Flags] and does not have value 10 defined, to create MyEnum with value 10 one must call MyEnum(10, True). Here True is an unnamed parameter, that allows unchecked conversion
- legacy behavior has been moved to a codec (EnumPyLongCodec); enums can now be encoded by codecs
- flags enums support bitwise ops via EnumOps class
@LeeDongGeon1996 LeeDongGeon1996 mentioned this issue Sep 10, 2021
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@LeeDongGeon1996
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LeeDongGeon1996 commented Sep 18, 2021 •
edited
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I think this should be a hot fix.

If there is C# codes like the below:

namespace myname.mynamespace
{
    public static partial class MyClass
    {
        public static IEnumerable<MyResult> MyFunc<TSometing>(
            this IEnumerable<TSomething> something,
            int num)
            where TSomething : ISomething
        {
             // do something.
        }

        public static IEnumerable<MyResult> MyFunc<TSometing>(
            this IEnumerable<TSomething> something,
            int num,
            MyEnum myenum = MyEnum.Elem)
            where TSomething : ISomething
        {
              // do something.
        }
    }
}

The second overloaded method can never be called:

from myname.mynamespace import MyClass
from myname.mynamespace import MyEnum

#Something is sub-class of ISomething .
MyClass.MyFunc[Something](something_list, 10, MyEnum.Elem2)

>>>
TypeError: No method matches given arguments for MyFunc: (<class 'System.Collections.Generic.0, Culture=neutral, PublicKeyToken=null]]'>, <class 'int'>, <class 'int'>)

I also tried to call the second one manually by using Overload(__overload__), fetching Type from System.Reflection, it doesn't work

@lostmsu
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lostmsu commented Sep 18, 2021

@LeeDongGeon1996 this has already been fixed in pythonnet 3.0 previews. We do not plan to backport it.

@lostmsu lostmsu closed this as completed Sep 18, 2021
@LeeDongGeon1996
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LeeDongGeon1996 commented Sep 22, 2021 •
edited
Loading

@lostmsu Thanks. But, I have a problem with using 3.0 preview.
I'm using it on Anaconda env with Mono on Mac. Is there any way to install preview with conda install -c conda-forge command?

russleikis added a commit to Ophir-Spiricon/BP-Automation that referenced this issue Feb 14, 2024
@russleikis
Simply the usage of enumerations in Datasource class to no longer add…
7337dfe 
…ress the integer values per Pythonnet v3.0 changes

pythonnet/pythonnet#1220
@russleikis russleikis mentioned this issue Feb 14, 2024
Closed
@ArthurAsenheimer ArthurAsenheimer mentioned this issue Mar 13, 2025
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