bpy.data.libraries.load returns bpy_lib and not 2 objects #96212

New Issue

Daniel Santana · 2022-03-07T12:19:42+01:00

Daniel Santana commented

2022-03-07 12:19:42 +01:00

System Information
Operating system: Windows-10-10.0.22000-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 511.79

Blender Version
Broken: version: 3.2.0 Alpha, branch: master, commit date: 2022-03-07 06:49, hash: ad2948face
Worked: (newest version of Blender that worked as expected)

Short description of error
When doing a link library load, the return python object is bpy_lib and not 2 objects. Also this objects doesn't seem to be fully exposed to python since it doesn't have any methods.

Exact steps for others to reproduce the error

Open factory default blender.
Go to Scripting tab and create the following script:

import bpy
import os
filename =  os.path.join(os.path.expandvars('$TMP'), 'test.blend')

bpy.data.libraries.write(filename, set(bpy.context.selected_objects), fake_user=True)

with bpy.data.libraries.load(filename, link=True) as (data_from, data_to):
    data_to.objects = data_from.objects

Execute and an error should occur, stating that bpy_lib is not iterable

PS: This happens with any file

**System Information** Operating system: Windows-10-10.0.22000-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 3060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 511.79 **Blender Version** Broken: version: 3.2.0 Alpha, branch: master, commit date: 2022-03-07 06:49, hash: `ad2948face` Worked: (newest version of Blender that worked as expected) **Short description of error** When doing a link library load, the return python object is bpy_lib and not 2 objects. Also this objects doesn't seem to be fully exposed to python since it doesn't have any methods. **Exact steps for others to reproduce the error** 1. Open factory default blender. 2. Go to Scripting tab and create the following script: ``` import bpy import os filename = os.path.join(os.path.expandvars('$TMP'), 'test.blend') bpy.data.libraries.write(filename, set(bpy.context.selected_objects), fake_user=True) with bpy.data.libraries.load(filename, link=True) as (data_from, data_to): data_to.objects = data_from.objects ``` 3. Execute and an error should occur, stating that bpy_lib is not iterable PS: This happens with any file

Daniel Santana commented

2022-03-07 12:19:42 +01:00

Added subscriber: @dgsantana

Philipp Oeser commented

2022-03-07 12:39:12 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2022-03-07 12:39:12 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Philipp Oeser commented

2022-03-07 12:39:12 +01:00

Just checking if the filename path really exists? (on my linux, I dont have $TMP defined).
Does the following equally fail for you? (this is working fine on my end -- meaning it does not error and prints the selected objects in the end...)

import bpy
import os
filename =  os.path.join(bpy.app.tempdir, 'test.blend')
print(filename)

bpy.data.libraries.write(filename, set(bpy.context.selected_objects), fake_user=True)

with bpy.data.libraries.load(filename, link=True) as (data_from, data_to):
    data_to.objects = data_from.objects
    
print(data_to.objects)

Just checking if the filename path really exists? (on my linux, I dont have $TMP defined). Does the following equally fail for you? (this is working fine on my end -- meaning it does not error and prints the selected objects in the end...) ``` import bpy import os filename = os.path.join(bpy.app.tempdir, 'test.blend') print(filename) bpy.data.libraries.write(filename, set(bpy.context.selected_objects), fake_user=True) with bpy.data.libraries.load(filename, link=True) as (data_from, data_to): data_to.objects = data_from.objects print(data_to.objects) ```

Daniel Santana commented

2022-03-07 13:02:53 +01:00

Sorry, my bad about the path I was using windows. Weird that worked, my blender should have been in a weird state.
But still happens in a larger script.

import os
import bpy
bl_info = {
    "name": "Export and Link",
    "author": "Daniel Santana",
    "version": (1, 0),
    "blender": (2, 80, 0),
    "location": "File > Export > Export and Link",
    "description": "Export and links the selected objects",
    "warning": "",
    "doc_url": "",
    "category": "Import-Export",
}

def write_lib_link(context, filepath:str, link:bool):
    
    bpy.data.libraries.write(filepath, set(context.selected_objects), fake_user=True)
    if link:
        bpy.ops.object.delete(use_global=False)
        with bpy.data.libraries.load(filepath, link=link) as (data_from, data_to):
            data_to.objects = data_from.objects
        for obj in data_to:
            context.view_layer.active_layer_collection.collection.objects.link(obj)

    return {'FINISHED'}


- ExportHelper is a helper class, defines filename and
- invoke() function which calls the file selector.
from bpy_extras.io_utils import ExportHelper
from bpy.props import StringProperty, BoolProperty, EnumProperty
from bpy.types import Operator


class ExportAndLink(Operator, ExportHelper):
    """This appears in the tooltip of the operator and in the generated docs"""
    bl_idname = "export.export_and_link"  # important since its how bpy.ops.import_test.some_data is constructed
    bl_label = "Export And Link"

    # ExportHelper mixin class uses this
    filename_ext = ".blend"

    filter_glob: StringProperty(
        default="*.blend",
        options={'HIDDEN'},
        maxlen=255,  # Max internal buffer length, longer would be clamped.
    )

    - List of operator properties, the attributes will be assigned
    - to the class instance from the operator settings before calling.
    use_setting: BoolProperty(
        name="Export and Link",
        description="Exports and links the selected objects.",
        default=True,
    )

    type: EnumProperty(
        name="Example Enum",
        description="Choose between two items",
        items=(
            ('OPT_A', "First Option", "Description one"),
            ('OPT_B', "Second Option", "Description two"),
        ),
        default='OPT_A',
    )

    def execute(self, context):
        return write_lib_link(context, self.filepath, self.use_setting)


# Only needed if you want to add into a dynamic menu
def menu_func_export(self, context):
    self.layout.operator(ExportAndLink.bl_idname, text="Export and Link")

# Register and add to the "file selector" menu (required to use F3 search "Text Export Operator" for quick access)
def register():
    bpy.utils.register_class(ExportAndLink)
    bpy.types.TOPBAR_MT_file_export.append(menu_func_export)


def unregister():
    bpy.utils.unregister_class(ExportAndLink)
    bpy.types.TOPBAR_MT_file_export.remove(menu_func_export)


if __name__ == "__main__":
    register()

    # test call
    bpy.ops.export.export_and_link('INVOKE_DEFAULT')

Sorry, my bad about the path I was using windows. Weird that worked, my blender should have been in a weird state. But still happens in a larger script. ``` import os import bpy bl_info = { "name": "Export and Link", "author": "Daniel Santana", "version": (1, 0), "blender": (2, 80, 0), "location": "File > Export > Export and Link", "description": "Export and links the selected objects", "warning": "", "doc_url": "", "category": "Import-Export", } def write_lib_link(context, filepath:str, link:bool): bpy.data.libraries.write(filepath, set(context.selected_objects), fake_user=True) if link: bpy.ops.object.delete(use_global=False) with bpy.data.libraries.load(filepath, link=link) as (data_from, data_to): data_to.objects = data_from.objects for obj in data_to: context.view_layer.active_layer_collection.collection.objects.link(obj) return {'FINISHED'} - ExportHelper is a helper class, defines filename and - invoke() function which calls the file selector. from bpy_extras.io_utils import ExportHelper from bpy.props import StringProperty, BoolProperty, EnumProperty from bpy.types import Operator class ExportAndLink(Operator, ExportHelper): """This appears in the tooltip of the operator and in the generated docs""" bl_idname = "export.export_and_link" # important since its how bpy.ops.import_test.some_data is constructed bl_label = "Export And Link" # ExportHelper mixin class uses this filename_ext = ".blend" filter_glob: StringProperty( default="*.blend", options={'HIDDEN'}, maxlen=255, # Max internal buffer length, longer would be clamped. ) - List of operator properties, the attributes will be assigned - to the class instance from the operator settings before calling. use_setting: BoolProperty( name="Export and Link", description="Exports and links the selected objects.", default=True, ) type: EnumProperty( name="Example Enum", description="Choose between two items", items=( ('OPT_A', "First Option", "Description one"), ('OPT_B', "Second Option", "Description two"), ), default='OPT_A', ) def execute(self, context): return write_lib_link(context, self.filepath, self.use_setting) # Only needed if you want to add into a dynamic menu def menu_func_export(self, context): self.layout.operator(ExportAndLink.bl_idname, text="Export and Link") # Register and add to the "file selector" menu (required to use F3 search "Text Export Operator" for quick access) def register(): bpy.utils.register_class(ExportAndLink) bpy.types.TOPBAR_MT_file_export.append(menu_func_export) def unregister(): bpy.utils.unregister_class(ExportAndLink) bpy.types.TOPBAR_MT_file_export.remove(menu_func_export) if __name__ == "__main__": register() # test call bpy.ops.export.export_and_link('INVOKE_DEFAULT') ```

Pratik Borhade commented

2022-03-07 13:10:24 +01:00

Added subscriber: @PratikPB2123

Campbell Barton commented

2022-03-07 13:19:58 +01:00

Added subscriber: @ideasman42

Campbell Barton commented

2022-03-07 13:19:58 +01:00

Changed status from 'Needs User Info' to: 'Archived'

Campbell Barton closed this issue

2022-03-07 13:19:58 +01:00

Campbell Barton commented

2022-03-07 13:19:58 +01:00

This isn't a bug for obj in data_to: should be for obj in data_to.objects:.

This isn't a bug `for obj in data_to:` should be `for obj in data_to.objects:`.

Daniel Santana commented

2022-03-07 13:35:33 +01:00

Thanks Campbell,
Sorry for my mistake. Even though it shouldn't leave blender in a weird state, because any subsequent calls to bpy.data.libraries.load stop working.

Thanks Campbell, Sorry for my mistake. Even though it shouldn't leave blender in a weird state, because any subsequent calls to `bpy.data.libraries.load` stop working.

Campbell Barton commented

2022-03-07 14:14:39 +01:00

@dgsantana could you please report a bug with a script to redo the error.

Daniel Santana commented

2022-03-07 15:10:44 +01:00

Ok course.

Daniel Santana commented

2022-03-07 15:22:20 +01:00

Ok, maybe it's just bad usage on my part, I was doing this on the console, which gives the error, so it only works with with context:

import os
bpy.data.libraries.write(filename, set(bpy.context.selected_objects), fake_user=True)
d,f = bpy.data.libraries.load(filename, link=True)

Ok, maybe it's just bad usage on my part, I was doing this on the console, which gives the error, so it only works with `with` context: ``` import os bpy.data.libraries.write(filename, set(bpy.context.selected_objects), fake_user=True) d,f = bpy.data.libraries.load(filename, link=True) ```

Campbell Barton commented

2022-03-08 06:18:11 +01:00

Right, you'll need to use a context manager.

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bpy.data.libraries.load returns bpy_lib and not 2 objects #96212