Merge pull request #130 from loggi/fgm-optimize-getattr

chore(enums) Optimize member check and dynamic creation of `is_<name>` properties

Author: fgmacedo

choicesenum/enums.py

@@ -5,8 +5,24 @@
 from enum import Enum, EnumMeta
 
 
+def is_member_factory(enum_member):
+    "Return a property that checks if the current enum is the expected one"
+    @property
+    def is_member(self):
+        return self == enum_member
+    return is_member
+
+
 class ChoicesMetaClass(EnumMeta):
 
+    def __new__(metacls, cls, bases, classdict):
+        enum_class = EnumMeta.__new__(metacls, cls, bases, classdict)
+        for name, enum_value in enum_class._member_map_.items():
+            prop_name = 'is_{}'.format(name.lower())
+            setattr(enum_class, prop_name, is_member_factory(enum_value))
+
+        return enum_class
+
     def __contains__(cls, member):
         if not isinstance(member, cls):
             try:
@@ -25,13 +41,6 @@ def __new__(cls, value, display=None):
         obj._display_ = display
         return obj
 
-    def __getattr__(self, item):
-        is_attr = 'is_'
-        if item.startswith(is_attr) and item in self._get_dynamic_property_names():
-            search = item[len(is_attr):]
-            return search == self._name_.lower()
-        raise AttributeError("'{}' object has no attribute '{}'".format(type(self).__name__, item))
-
     def __str__(self):
         return str(self.value)
 
@@ -75,14 +84,6 @@ def __gt__(self, other):
     def __ge__(self, other):
         return self.value >= self._get_value(other)
 
-    def __dir__(self):
-        return sorted(set(
-            dir(type(self)) +
-            list(self.__dict__.keys()) +
-            ['display', 'get_choices', ] +
-            list(self._get_dynamic_property_names())
-        ))
-
     def __json__(self):
         """
         If you want json serialization, you have at least two options:
@@ -114,14 +115,6 @@ def description(self):
         """
         return self.display
 
-    @classmethod
-    def _get_dynamic_property_names(cls):
-        """
-        Args:
-            cls (Enum): Enum class.
-        """
-        return ('is_{}'.format(x._name_.lower()) for x in cls)
-
     @classmethod
     def choices(cls):
         """

tests/test_choicesenum.py

@@ -68,11 +68,16 @@ def test_dynamic_is_attr_of_undefined_enums_should_fail(colors):
         assert colors.RED.is_banana
 
 
-@pytest.mark.parametrize('attr', ['RED', 'BLUE', 'GREEN', 'is_red', 'is_blue', 'is_green'])
+@pytest.mark.parametrize('attr', ['is_red', 'is_blue', 'is_green'])
 def test_dynamic_is_attr_should_be_in_dir(colors, attr):
         assert attr in dir(colors.RED)
 
 
+@pytest.mark.parametrize('attr', ['RED', 'BLUE', 'GREEN'])
+def test_enum_type_name_should_be_in_dir(colors, attr):
+        assert attr in dir(colors)
+
+
 @pytest.mark.skipif(sys.version_info < (3, 0), reason="requires python3")
 def test_in_format_python3(colors):
     assert '{}'.format(colors.RED) == "#f00"