text: from __future__ import unicode_literals
  import frappe
  
  def execute():
  	frappe.reload_doctype('Event')
  	# Rename "Cancel" to "Cancelled"
  	frappe.db.sql("""UPDATE tabEvent set event_type='Cancelled' where event_type='Cancel'""")
  	# Move references to Participants table
  	events = frappe.db.sql("""SELECT name, ref_type, ref_name FROM tabEvent WHERE ref_type!=''""", as_dict=True)
  	for event in events:
  		if event.ref_type and event.ref_name:
  			try:
  				e = frappe.get_doc('Event', event.name)
  				e.append('event_participants', {"reference_doctype": event.ref_type, "reference_docname": event.ref_name})
  				e.flags.ignore_mandatory   = True
  				e.flags.ignore_permissions = True
  				e.save()
  			except Exception:
  				frappe.log_error(frappe.get_traceback())