add magic methods

michaelliao · michaelliao · commit 2ac43de992b8 · 2015-04-01T13:47:47.000+08:00
diff --git a/py3/oop_advance/special_call.py b/py3/oop_advance/special_call.py
@@ -0,0 +1,12 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+class Student(object):
+    def __init__(self, name):
+        self.name = name
+
+    def __call__(self):
+        print('My name is %s.' % self.name)
+
+s = Student('Michael')
+s()
diff --git a/py3/oop_advance/special_getattr.py b/py3/oop_advance/special_getattr.py
@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+class Student(object):
+
+    def __init__(self):
+        self.name = 'Michael'
+
+    def __getattr__(self, attr):
+        if attr=='score':
+            return 99
+        if attr=='age':
+            return lambda: 25
+        raise AttributeError('\'Student\' object has no attribute \'%s\'' % attr)
+
+s = Student()
+print(s.name)
+print(s.score)
+print(s.age())
+# AttributeError: 'Student' object has no attribute 'grade'
+print(s.grade)
diff --git a/py3/oop_advance/special_getitem.py b/py3/oop_advance/special_getitem.py
@@ -0,0 +1,30 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+class Fib(object):
+
+    def __getitem__(self, n):
+        if isinstance(n, int):
+            a, b = 1, 1
+            for x in range(n):
+                a, b = b, a + b
+            return a
+        if isinstance(n, slice):
+            start = n.start
+            stop = n.stop
+            if start is None:
+                start = 0
+            a, b = 1, 1
+            L = []
+            for x in range(stop):
+                if x >= start:
+                    L.append(a)
+                a, b = b, a + b
+            return L
+
+f = Fib()
+print(f[0])
+print(f[5])
+print(f[100])
+print(f[0:5])
+print(f[:10])
diff --git a/py3/oop_advance/special_iter.py b/py3/oop_advance/special_iter.py
@@ -0,0 +1,19 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+class Fib(object):
+
+    def __init__(self):
+        self.a, self.b = 0, 1 # &#21021;&#22987;&#21270;&#20004;&#20010;&#35745;&#25968;&#22120;a&#65292;b
+
+    def __iter__(self):
+        return self # &#23454;&#20363;&#26412;&#36523;&#23601;&#26159;&#36845;&#20195;&#23545;&#35937;&#65292;&#25925;&#36820;&#22238;&#33258;&#24049;
+
+    def __next__(self):
+        self.a, self.b = self.b, self.a + self.b # &#35745;&#31639;&#19979;&#19968;&#20010;&#20540;
+        if self.a > 100000: # &#36864;&#20986;&#24490;&#29615;&#30340;&#26465;&#20214;
+            raise StopIteration();
+        return self.a # &#36820;&#22238;&#19979;&#19968;&#20010;&#20540;
+
+for n in Fib():
+    print(n)
diff --git a/py3/oop_advance/special_str.py b/py3/oop_advance/special_str.py
@@ -0,0 +1,14 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+class Student(object):
+
+    def __init__(self, name):
+        self.name = name
+
+    def __str__(self):
+        return 'Student object (name: %s)' % self.name
+
+    __repr__ = __str__
+
+print(Student('Michael'))
diff --git a/py3/oop_advance/use_property.py b/py3/oop_advance/use_property.py
@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+class Student(object):
+
+    @property
+    def score(self):
+        return self._score
+
+    @score.setter
+    def score(self, value):
+        if not isinstance(value, int):
+            raise ValueError('score must be an integer!')
+        if value < 0 or value > 100:
+            raise ValueError('score must between 0 ~ 100!')
+        self._score = value
+
+s = Student()
+s.score = 60
+print('s.score =', s.score)
+# ValueError: score must between 0 ~ 100!
+s.score = 9999
