text: from __future__ import unicode_literals
  import frappe
  
  from frappe.model.utils.rename_field import rename_field
  
  def execute():
  	""" 
  		Rename Total Margin field to Rate With Margin in
  		"Sales Order Item", "Sales Invoice Item", "Delivery Note Item",
  		"Quotation Item"
  	"""
  
  	for d in ("Sales Order Item", "Sales Invoice Item",
  		"Delivery Note Item", "Quotation Item"):
  		frappe.reload_doctype(d)
  		rename_field_if_exists(d, "total_margin", "rate_with_margin")
  
  
  def rename_field_if_exists(doctype, old_fieldname, new_fieldname):
  	try:
  		rename_field(doctype, old_fieldname, new_fieldname)
  	except Exception as e:
  		if e.args[0] != 1054:
  			raise
  