add slots sample

michaelliao · michaelliao · commit a435e6317047 · 2015-04-01T13:33:26.000+08:00
diff --git a/py3/oop_advance/use_slots.py b/py3/oop_advance/use_slots.py
@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+class Student(object):
+    __slots__ = ('name', 'age') # &#29992;tuple&#23450;&#20041;&#20801;&#35768;&#32465;&#23450;&#30340;&#23646;&#24615;&#21517;&#31216;
+
+class GraduateStudent(Student):
+    pass
+
+s = Student() # &#21019;&#24314;&#26032;&#30340;&#23454;&#20363;
+s.name = 'Michael' # &#32465;&#23450;&#23646;&#24615;'name'
+s.age = 25 # &#32465;&#23450;&#23646;&#24615;'age'
+# ERROR: AttributeError: 'Student' object has no attribute 'score'
+try:
+    s.score = 99
+except AttributeError as e:
+    print('AttributeError:', e)
+
+g = GraduateStudent()
+g.score = 99
+print('g.score =', g.score)
