Create a new empty ArcGIS map document (.mxd) with Python (comtypes)

create_mxd_comtypes.py

from comtypes.client import GetModule, CreateObject
from snippets102 import GetStandaloneModules, InitStandalone

esriCarto = GetModule(r"C:\Program Files (x86)\ArcGIS\Desktop10.5\com\esriCarto.olb")

# First time through, need to import the “StandaloneModules”. Can comment out later.
GetStandaloneModules()
InitStandalone()

# Create a map document object
mxdObject = CreateObject(esriCarto.MapDocument, interface=esriCarto.IMapDocument)

# Create new mxd file
mxdObject.New(r'C:\Temp\MapTemplate.mxd')

mxdObject.Save()