More magic and clean up

CHANGELOG.rst

@@ -2,6 +2,13 @@
 Changelog
 =========
 
+0.13.0 (2015-04-25)
+-------------------
+  - New feature: Decorator type_safe to check function arguments
+  - New feature: combine_class function takes name for new class as first argument
+  - Refactoring magic.py to look less like black magic
+  - Improving errors.py exception class creation to accept custom messages
+
 0.12.0 (2015-04-22)
 -------------------
   - New feature: Rename of composed traits

setup.py

@@ -13,6 +13,7 @@
 from setuptools import find_packages
 from setuptools import setup
 
+
 def read(*names, **kwargs):
     return io.open(
         join(dirname(__file__), *names),
@@ -22,7 +23,7 @@ def read(*names, **kwargs):
 
 setup(
     name='py3traits',
-    version='0.10.0',
+    version='0.13.0',
     license='Apache License 2',
     description='Trait support for Python 3',
     long_description='%s\n%s' % (read('README.rst'), re.sub(':obj:`~?(.*?)`', r'``\1``', read('CHANGELOG.rst'))),

src/pytraits/__init__.py

@@ -16,10 +16,11 @@
    limitations under the License.
 '''
 
-from pytraits.core import Singleton
+from pytraits.core import Singleton, type_safe, type_converted
 from pytraits.combiner import combine_class
 from pytraits.extendable import extendable
 from pytraits.trait_composer import add_traits
 
-__version__ = "0.1.0"
-__all__ = ["Singleton", "combine_class", "extendable", "add_traits"]
+__version__ = "0.13.0"
+__all__ = ["Singleton", "combine_class", "extendable", "add_traits",
+           "type_safe", "type_converted"]

src/pytraits/combiner.py

@@ -19,7 +19,7 @@
 from pytraits.trait_composer import add_traits
 
 
-def combine_class(*traits, **resolved_conflicts):
+def combine_class(class_name, *traits, **resolved_conflicts):
     """
     This function composes new class out of any number of traits.
 
@@ -32,12 +32,15 @@ def combine_class(*traits, **resolved_conflicts):
     >>> class Three:
     ...     def third(self): return 3
     ...
-    >>> Combination = combine_class(One, Two, Three)
+    >>> Combination = combine_class("Combination", One, Two, Three)
     >>> instance = Combination()
     >>> instance.first(), instance.second(), instance.third()
     (1, 2, 3)
+
+    >>> instance.__class__.__name__
+    'Combination'
     """
-    NewClass = type("NewClass", (object,), {})
+    NewClass = type(class_name, (object,), {})
     add_traits(NewClass, *traits)
     return NewClass
 

src/pytraits/core/__init__.py

@@ -18,6 +18,6 @@
 
 from pytraits.core.singleton import Singleton
 from pytraits.core.utils import flatten
-from pytraits.core.magic import type_converted
+from pytraits.core.magic import type_safe, type_converted
 
-__all__ = ["Singleton", "flatten", "type_converted"]
+__all__ = ["Singleton", "flatten", "type_safe", "type_converted"]

src/pytraits/core/errors.py

@@ -18,17 +18,19 @@
 
 # Exceptions
 UnextendableObjectError = "Target context can be only class or instance of class"
-InvalidAssignmentError = "Not possible to assign a key"
-SingletonError = 'Singletons are immutable'
+SingletonError = 'Singletons are immutable!'
 BuiltinSourceError = 'Built-in objects can not used as traits!'
 PropertySourceError = 'Properties can not be extended!'
+TypeConversionError = 'Conversion impossible!'
 
 
 # Convert strings to exception objects
 for exception, message in dict(globals()).items():
     if not exception.endswith('Error'):
         continue
+
     bases = (Exception,)
-    attrs = {'_MSG': message,
-             '__str__': lambda self: self._MSG}
+    attrs = {'__default_msg': message,
+             '__init__': lambda self, msg=None: setattr(self, '__msg', msg),
+             '__str__': lambda self: self.__msg or self.__default_msg}
     globals()[exception] = type(exception, bases, attrs)