update from atlas

21-class-metaprog/evaldecos.py

@@ -0,0 +1,22 @@
+def deco_alpha(func):
+    print('<<100>> deco_alpha')
+
+    def inner_alpha():
+        print('<<200>> deco_alpha')
+        func()
+
+    return inner_alpha
+
+
+def deco_beta(cls):
+    print('<<300>> deco_beta')
+
+    def inner_beta(self):
+        print('<<400>> inner_beta')
+        print("result from 'deco_beta::inner_beta'")
+
+    cls.method3 = inner_beta
+    return cls
+
+
+print('<<500>> evaldecos mudule body')

21-class-metaprog/evaltime.py

@@ -0,0 +1,92 @@
+import atexit
+
+from evaldecos import deco_alpha
+from evaldecos import deco_beta
+
+
+print('<<1>> start')
+
+
+func_A = lambda: print('<<2>> func_A')
+
+
+def func_B():
+    print('<<3>> func_B')
+
+    def func_C():
+        print('<<4>> func_C')
+
+    return func_C
+
+
+@deco_alpha
+def func_D():
+    print('<<6>> func_D')
+
+
+def func_E():
+    print('<<7>> func_E')
+
+
+class ClassOne(object):
+    print('<<7>> ClassOne body')
+
+    def __init__(self):
+        print('<<8>> ClassOne.__init__')
+
+    def __del__(self):
+        print('<<9>> ClassOne.__del__')
+
+    def method1(self):
+        print('<<10>> ClassOne.method')
+        return "result from 'ClassOne.method1'"
+
+    class ClassTwo(object):
+        print('<<11>> ClassTwo body')
+
+
+@deco_beta
+class ClassThree(ClassOne):
+    print('<<12>> ClassThree body')
+
+    def method3(self):
+        print('<<13>> ClassOne.method')
+        return "result from 'ClassThree.method3'"
+
+
+if True:
+    print("<<14>> 'if True'")
+
+
+if False:
+    print("<<15>> 'if False'")
+
+
+atexit.register(func_E)
+
+print("<<16>> right before 'if ... __main__'")
+
+
+if __name__ == '__main__':
+    print('<<17>> start __main__ block')
+    print(func_A)
+    print(func_A())
+    print('<<18>> continue __main__ block')
+    print(func_B)
+    b_result = func_B()
+    print(b_result)
+    one = ClassOne()
+    one.method1()
+    b_result()
+    print(func_D)
+    func_D()
+    three = ClassThree()
+    three.method3()
+
+    class ClassFour(object):
+        print('<<19>> ClasFour body')
+
+    print('<<20>> end __main__ block')
+
+
+print('<<21>> The End')

21-class-metaprog/factories.py

@@ -0,0 +1,50 @@
+"""
+record_factory: create simple classes just for holding data fields
+
+# BEGIN RECORD_FACTORY_DEMO
+    >>> Dog = record_factory('Dog', 'name weight owner')  # <1>
+    >>> rex = Dog('Rex', 30, 'Bob')
+    >>> rex  # <2>
+    Dog(name='Rex', weight=30, owner='Bob')
+    >>> name, weight, _ = rex  # <3>
+    >>> name, weight
+    ('Rex', 30)
+    >>> "{2}'s dog weights {1}kg".format(*rex)
+    "Bob's dog weights 30kg"
+    >>> rex.weight = 32  # <4>
+    >>> rex
+    Dog(name='Rex', weight=32, owner='Bob')
+    >>> Dog.__mro__  # <5>
+    (<class 'factories.Dog'>, <class 'object'>)
+
+# END RECORD_FACTORY_DEMO
+"""
+
+# BEGIN RECORD_FACTORY
+def record_factory(cls_name, field_names):
+    if isinstance(field_names, str):  # <1>
+        field_names = field_names.replace(',', ' ').split()
+    __slots__ = tuple(field_names)
+
+    def __init__(self, *args, **kwargs):
+        attrs = dict(zip(self.__slots__, args))
+        attrs.update(kwargs)
+        for name, value in attrs.items():
+            setattr(self, name, value)
+
+    def __iter__(self):
+        for name in self.__slots__:
+            yield getattr(self, name)
+
+    def __repr__(self):
+        values = ', '.join('{}={!r}'.format(*i) for i
+                           in zip(self.__slots__, self))
+        return '{}({})'.format(self.__class__.__name__, values)
+
+    cls_attrs = dict(__slots__ = __slots__,
+                     __init__ = __init__,
+                     __iter__ = __iter__,
+                     __repr__ = __repr__)
+
+    return type(cls_name, (object,), cls_attrs)
+# END RECORD_FACTORY