brotherton-erpnext/erpnext/patches/v14_0/migrate_cost_center_allocations.py

import frappe
from frappe.utils import today

def execute():
	for dt in ("cost_center_allocation", "cost_center_allocation_percentage"):
		frappe.reload_doc('accounts', 'doctype', dt)

	cc_allocations = get_existing_cost_center_allocations()
	if cc_allocations:
		create_new_cost_center_allocation_records(cc_allocations)

	frappe.delete_doc('DocType', 'Distributed Cost Center', ignore_missing=True)

def create_new_cost_center_allocation_records(cc_allocations):
	for main_cc, allocations in cc_allocations.items():
		cca = frappe.new_doc("Cost Center Allocation")
		cca.main_cost_center = main_cc
		cca.valid_from = today()

		for child_cc, percentage in allocations.items():
			cca.append("allocation_percentages", ({
				"cost_center": child_cc,
				"percentage": percentage
			}))
		
		cca.save()
		cca.submit()

def get_existing_cost_center_allocations():
	if not frappe.get_meta("Cost Center").has_field("enable_distributed_cost_center"):
		return

	par = frappe.qb.DocType("Cost Center")
	child = frappe.qb.DocType("Distributed Cost Center")

	records = (
		frappe.qb.from_(par)
		.inner_join(child).on(par.name == child.parent)
		.select(par.name, child.cost_center, child.percentage_allocation)
		.where(par.enable_distributed_cost_center == 1)
	).run(as_dict=True)

	cc_allocations = frappe._dict()
	for d in records:
		cc_allocations.setdefault(d.name, frappe._dict())\
			.setdefault(d.cost_center, d.percentage_allocation)

	return cc_allocations