How to get operator defaults How do I get a list of default properties for an operator, similar to how the console autofill does, so bpy.ops.export_scene.fbx() gives:
check_existing=True,
filter_glob=&quot;*.fbx&quot;,
use_selection=False,
...
Operator property variables are defined as Python class annotations, so you can read those to find their defaults.
First, get the name of the class as registered:
&gt;&gt;&gt; bpy.ops.export_scene.fbx.idname()
'EXPORT_SCENE_OT_fbx'

Then use that to get operator class as defined in the script file:
&gt;&gt;&gt; getattr(bpy.types, bpy.ops.export_scene.fbx.idname())
&lt;class 'io_scene_fbx.ExportFBX'&gt;

And lastly, read the type annotations on that:
&gt;&gt;&gt; getattr(bpy.types, bpy.ops.export_scene.fbx.idname()).__annotations__

The results from this are a little long and also include information like minimum and maximum permissible values, so you may want to filter them through a dict comprehension to get something easier to use:
&gt;&gt;&gt; {k:v[1].get(&quot;default&quot;, None) for k, v in getattr(bpy.types, bpy.ops.export_scene.fbx.idname()).__annotations__.items()}
{'filter_glob': '*.fbx', 'use_selection': False, 'use_active_collection': False, 'global_scale': 1.0, 'apply_unit_scale': True, 'apply_scale_options': None, 'use_space_transform': True, 'bake_space_transform': False, 'object_types': {'CAMERA', 'EMPTY', 'ARMATURE', 'OTHER', 'MESH', 'LIGHT'}, 'use_mesh_modifiers': True, 'use_mesh_modifiers_render': True, 'mesh_smooth_type': 'OFF', 'use_subsurf': False, 'use_mesh_edges': False, 'use_tspace': False, 'use_custom_props': False, 'add_leaf_bones': True, 'primary_bone_axis': 'Y', 'secondary_bone_axis': 'X', 'use_armature_deform_only': False, 'armature_nodetype': 'NULL', 'bake_anim': True, 'bake_anim_use_all_bones': True, 'bake_anim_use_nla_strips': True, 'bake_anim_use_all_actions': True, 'bake_anim_force_startend_keying': True, 'bake_anim_step': 1.0, 'bake_anim_simplify_factor': 1.0, 'path_mode': 'AUTO', 'embed_textures': False, 'batch_mode': None, 'use_batch_own_dir': True, 'use_metadata': True, 'axis_forward': '-Z', 'axis_up': 'Y'}