To expand on @amball's answer. It took me a few hours to figure out how to change one of the setting with Python so I am posting this here. Note: I am using ArcGIS 10.3
The ArcPy API does not have access to modify all the properties of an address locator.
You will need to edit the myLocator.loc.xml directly using a xml parser.
Note: The white space in an xml document does not have an effect on its meaning also the nodes can be moved around with out changing its semantics. To have a more robust program you need to use software that is aware of this and in this case use an xml parser.
Here is an example to change the Minimum Match Score of an Address Locator.
from xml.dom import minidom
locator_path = "AddressLocators\myLocator.loc.xml"
minimum_match_score = 99
xmldoc = minidom.parse(locator_path)
properties = xmldoc.getElementsByTagName("prop")
for p in properties:
if p.getAttribute('name') == 'MinimumMatchScore':
with open(locator_path,'w') as f: