def func1(list1,list2,str1): if len(list1)> 3: list1 = list1[:3] list2[0] = 'goodbye' str1 = ''.join(list2) print("ids:{:<15d},{:<15d},{:<15d}".format(id(list1),id(list2),id(str1))) arg1_list = ['a','b','c','d'] arg2_list = ['hello','mother','and','father'] arg_str = 'sister' print("############################") print("ids:{:<15d},{:<15d},{:<15d}".format(id(arg1_list),id(arg2_list),id(arg_str))) print("############################") func1(arg1_list, arg2_list, arg_str) print(arg1_list) # Line 1 print(arg2_list) # Line 2 print(arg_str) # Line 3 print("############################") print("ids:{:<15d},{:<15d},{:<15d}".format(id(arg1_list),id(arg2_list),id(arg_str)))