added catalog pattern

diopib · diopib · commit 11b4b6ada24d · 2013-11-27T12:24:11.000-05:00
diff --git a/catalog.py b/catalog.py
@@ -0,0 +1,53 @@
+"""
+A class that uses different static function depending of a parameter passed in init
+Note the use of a single dictionnary instead of multiple conditions
+"""
+__author__ = "Ibrahim Diop <http://ibrahim.zinaria.com>"
+__gist__ = "<https://gist.github.com/diopib/7679559>"
+
+class Catalog():
+    """
+    catalog of multiple static methods that are executed depending on an init parameter
+    """
+
+    def __init__(self, param):
+
+        # dictionary that will be used to determine which static method is to be executed but
+        # that will be also used to store possible param value
+        self.static_method_choices = {'param_value_1': self.static_method_1, 'param_value_2': self.static_method_2}
+
+        # simple test to validate param value
+        if param in self.static_method_choices.keys():
+            self.param = param
+        else:
+            raise Exception("Invalid Value for Param: {0}".format(param))
+
+    @staticmethod
+    def static_method_1():
+        print("executed method 1!")
+
+    @staticmethod
+    def static_method_2():
+        print("executed method 2!")
+
+    def main_method(self):
+        """
+        will execute either static_method_1 or static_method_2
+        depending on self.param value
+        """
+        self.static_method_choices[self.param]()
+
+
+def main():
+    """
+    >>> c = Catalog('param_value_1').main_method()
+    executed method 1!
+    >>> Catalog('param_value_2').main_method()
+    executed method 2!
+    """
+
+    test = Catalog('param_value_2')
+    test.main_method()
+
+if __name__ == "__main__":
+    main()
