How to control spacing/alignment of Label + Horizontal Enum Property?

Question

I would like to achieve the layout of this panel but I'm having some issues. The example is from blender's Bevel Operator. As far as I can tell it's just an Enum Property without the enum_flag since only Vertices or Edges can be selected at a time:

First attempt:

layout = self.layout
row = layout.row()
row.label(text='My Prop');  row.prop(self, 'enum_prop', expand=True)

Looks pretty similar, just gotta align the label to the right.

Second Attempt:

layout = self.layout
row = layout.row()
split = row.split(factor=0.4)
left_col  = split.column(align=True)
right_col = split.column(align=True)
left_col.alignment  = 'RIGHT'
right_col.alignment = 'CENTER'
left_col.label(text='My Prop'); right_col.prop(self, 'enum_prop', expand=True)

Well, I managed to align things into columns but my Enum Prop is suddenly vertical. I figured I wasn't giving it enough room with the Split factor but that wasn't the case. How can I achieve the result from the first image?

(Label aligned to the Right + Horizontal Enum Prop)

EXTRA INFO:

If anyone is wondering, here is how I created the property:

enum_items = [  ('ON',  'On',  'Description1'), 
                ('OFF', 'Off', 'Description2')]
enum_prop: EnumProperty(name='My Prop', default='OFF', items=enum_items)

Answer 1

Just set layout.use_property_split property in your draw method to True:

def draw(self, context):
    layout = self.layout
    layout.use_property_split = True
    layout.use_property_decorate = False  # No animation.
    ...

---

Custom Panel

Example based on the add-on template from: How to create a custom UI?

bl_info = {
    "name": "Add-on Template",
    "description": "",
    "author": "p2or, brockmann",
    "version": (0, 0, 3),
    "blender": (2, 80, 0),
    "location": "3D View > Tools",
    "warning": "", # used for warning icon and text in addons panel
    "wiki_url": "",
    "tracker_url": "",
    "category": "Development"
}
import bpy
from bpy.props import (StringProperty,
                       BoolProperty,
                       IntProperty,
                       FloatProperty,
                       FloatVectorProperty,
                       EnumProperty,
                       PointerProperty,
                       )
from bpy.types import (Panel,
                       Menu,
                       Operator,
                       PropertyGroup,
                       )
------------------------------------------------------------------------
Scene Properties
------------------------------------------------------------------------
class MyProperties(PropertyGroup):
my_bool: BoolProperty(
    name="Enable or Disable",
    description="A bool property",
    default = False
    )

my_int: IntProperty(
    name = "Int Value",
    description="A integer property",
    default = 23,
    min = 10,
    max = 100
    )

my_float: FloatProperty(
    name = "Float Value",
    description = "A float property",
    default = 23.7,
    min = 0.01,
    max = 30.0
    )

my_float_vector: FloatVectorProperty(
    name = "Float Vector Value",
    description="Something",
    default=(0.0, 0.0, 0.0), 
    min= 0.0, # float
    max = 0.1
) 

my_string: StringProperty(
    name="User Input",
    description=":",
    default="",
    maxlen=1024,
    )

my_path: StringProperty(
    name = "Directory",
    description="Choose a directory:",
    default="",
    maxlen=1024,
    subtype='DIR_PATH'
    )

my_enum: EnumProperty(
    name="Dropdown:",
    description="Apply Data to attribute.",
    items=[ ('OP1', "Option 1", ""),
            ('OP2', "Option 2", ""),
           ]
    )


------------------------------------------------------------------------
Panel in Object Mode
------------------------------------------------------------------------
class OBJECT_PT_CustomPanel(Panel):
    bl_label = "My Panel"
    bl_idname = "OBJECT_PT_custom_panel"
    bl_space_type = "VIEW_3D"

    bl_region_type = "UI"
    bl_category = "Tools"
    bl_context = "objectmode"
@classmethod
def poll(self,context):
    return context.object is not None

def draw(self, context):
    layout = self.layout
    layout.use_property_split = True
    layout.use_property_decorate = False  # No animation.

    scene = context.scene
    mytool = scene.my_tool

    layout.prop(mytool, "my_bool")
    layout.prop(mytool, "my_enum", expand=True)
    layout.prop(mytool, "my_int")
    layout.prop(mytool, "my_float")
    layout.prop(mytool, "my_float_vector")
    layout.prop(mytool, "my_string")
    layout.prop(mytool, "my_path")



------------------------------------------------------------------------
Registration
------------------------------------------------------------------------
classes = (
    MyProperties,
    OBJECT_PT_CustomPanel
)
def register():
    from bpy.utils import register_class
    for cls in classes:
        register_class(cls)
bpy.types.Scene.my_tool = PointerProperty(type=MyProperties)


def unregister():
    from bpy.utils import unregister_class
    for cls in reversed(classes):
        unregister_class(cls)
    del bpy.types.Scene.my_tool
if name == "main":
    register()

---

Custom Operator

It's basically the same for the redo panel, you would have to create an extra row though:

import bpy
class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"
    bl_options = {'REGISTER', 'UNDO'}
my_enum: bpy.props.EnumProperty(
    name="Dropdown:",
    description="Apply Data to attribute.",
    items=[ ('OP1', "Option 1", ""),
            ('OP2', "Option 2", "")])

my_float: bpy.props.FloatProperty(
    name = "Float Value",
    description = "A float property",
    default = 23.7,
    min = 0.01,
    max = 30.0)


@classmethod
def poll(cls, context):
    return context.active_object is not None

def execute(self, context):
    print(self.bl_idname)
    return {'FINISHED'}

def draw(self, context):
    layout = self.layout
    layout.use_property_split = True
    layout.use_property_decorate = False  # No animation.

    row = layout.row(align=True)
    row.prop(self, "my_enum", expand=True)
    layout.prop(self, "my_float")



def register():
    bpy.utils.register_class(SimpleOperator)
def unregister():
    bpy.utils.unregister_class(SimpleOperator)
if name == "main":
    register()
# test call
#bpy.ops.object.simple_operator()