diff --git a/erpnext/crm/doctype/opportunity/opportunity.py b/erpnext/crm/doctype/opportunity/opportunity.py
index af1fc5c8792..c7b0304203c 100644
--- a/erpnext/crm/doctype/opportunity/opportunity.py
+++ b/erpnext/crm/doctype/opportunity/opportunity.py
@@ -30,17 +30,23 @@ class Opportunity(TransactionBase, CRMNote):
 
 		load_address_and_contact(ref_doc)
 		load_address_and_contact(self)
-		
-		ref_doc_contact_list = ref_doc.get("__onload").get('contact_list')
-		opportunity_doc_contact_list = [contact for contact in self.get('__onload').get('contact_list') if contact not in ref_doc_contact_list]
+
+		ref_doc_contact_list = ref_doc.get("__onload").get("contact_list")
+		opportunity_doc_contact_list = [
+			contact
+			for contact in self.get("__onload").get("contact_list")
+			if contact not in ref_doc_contact_list
+		]
 		ref_doc_contact_list.extend(opportunity_doc_contact_list)
 		ref_doc.set_onload("contact_list", ref_doc_contact_list)
 
-		ref_doc_addr_list = ref_doc.get("__onload").get('addr_list')
-		opportunity_doc_addr_list = [addr for addr in self.get('__onload').get('addr_list') if addr not in ref_doc_addr_list]
+		ref_doc_addr_list = ref_doc.get("__onload").get("addr_list")
+		opportunity_doc_addr_list = [
+			addr for addr in self.get("__onload").get("addr_list") if addr not in ref_doc_addr_list
+		]
 		ref_doc_addr_list.extend(opportunity_doc_addr_list)
 		ref_doc.set_onload("addr_list", ref_doc_addr_list)
-		
+
 		self.set("__onload", ref_doc.get("__onload"))
 
 	def after_insert(self):