Revert "Remove pyutilib.enum"

pyutilib/enum/__init__.py

@@ -8,11 +8,4 @@
 #  _________________________________________________________________________
 #
 
-import sys
-
-if 'nose' not in sys.modules and 'nose2' not in sys.modules:
-    raise ImportError("""pyutilib.enum has been removed.
-
-Python 3 now has an enum implementation in the standard library (also
-available for older Python versions as the third-party enum34 PyPI
-package) that supersedes this library.""")
+from pyutilib.enum.enum import Enum, EnumValue

pyutilib/enum/enum.py

@@ -0,0 +1,311 @@
+# -*- coding: utf-8 -*-
+
+# enum.py
+# Part of enum, a package providing enumerated types for Python.
+#
+# Copyright © 2007 Ben Finney
+# This is free software; you may copy, modify and/or distribute this work
+# under the terms of the GNU General Public License, version 2 or later
+# or, at your option, the terms of the Python license.
+#
+#  _________________________________________________________________________
+#
+#  PyUtilib: A Python utility library.
+#  Copyright (c) 2008 Sandia Corporation.
+#  This software is distributed under the BSD License.
+#  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
+#  the U.S. Government retains certain rights in this software.
+#  _________________________________________________________________________
+#
+# William Hart
+# Edits to the PyPI enum package to support __call__ and pickling.
+#
+""" Robust enumerated type support in Python.
+
+This package provides a module for robust enumerations in Python.
+
+An enumeration object is created with a sequence of string arguments
+to the Enum() constructor::
+
+    >>> from enum import Enum
+    >>> Colours = Enum('red', 'blue', 'green')
+    >>> Weekdays = Enum('mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun')
+
+The return value is an immutable sequence object with a value for each
+of the string arguments. Each value is also available as an attribute
+named from the corresponding string argument::
+
+    >>> pizza_night = Weekdays[4]
+    >>> shirt_colour = Colours.green
+
+The values are constants that can be compared only with values from
+the same enumeration; comparison with other values will invoke
+Python's fallback comparisons::
+
+    >>> pizza_night == Weekdays.fri
+    True
+    >>> shirt_colour > Colours.red
+    True
+    >>> shirt_colour == "green"
+    False
+
+Each value from an enumeration exports its sequence index
+as an integer, and can be coerced to a simple string matching the
+original arguments used to create the enumeration::
+
+    >>> str(pizza_night)
+    'fri'
+    >>> shirt_colour.index
+    2
+"""
+
+import six
+
+
+class EnumException(Exception):
+    """ Base class for all exceptions in this module. """
+
+    def __init__(self):
+        if self.__class__ is EnumException:
+            raise NotImplementedError("%s is an abstract class for subclassing"
+                                      % self.__class__)
+
+
+class EnumEmptyError(AssertionError, EnumException):
+    """ Raised when attempting to create an empty enumeration. """
+
+    def __str__(self):
+        return "Enumerations cannot be empty"
+
+
+class EnumBadKeyError(TypeError, EnumException):
+    """ Raised when creating an Enum with non-string keys. """
+
+    def __init__(self, key):
+        self.key = key
+
+    def __str__(self):
+        return ("Enumeration keys must be strings or "
+                "instances of EnumValue: %s" % (self.key,))
+
+
+class EnumBadIndexError(AssertionError, EnumException):
+    """ Raised when creating an Enum with with an invalid index."""
+
+    def __init__(self, index, reason):
+        self.index = index
+        self.reason = reason
+
+    def __str__(self):
+        return ("Enumeration index (%s) is not valid. Reason: %s" %
+                (self.index, self.reason))
+
+
+class EnumBadTypeError(TypeError, EnumException):
+    """ Raised when creating an Enum with a bad type value."""
+
+    def __init__(self, type_, reason):
+        self.type_ = type_
+        self.reason = reason
+
+    def __str__(self):
+        return ("Enumeration type=%r is not valid. Reason: %s" %
+                (self.type_, self.reason))
+
+
+class EnumImmutableError(TypeError, EnumException):
+    """ Raised when attempting to modify an Enum. """
+
+    def __init__(self, *args):
+        self.args = args
+
+    def __str__(self):
+        return "Enumeration does not allow modification"
+
+
+class EnumValue(object):
+    """ A specific value of an enumerated type. """
+
+    def __init__(self, enumtype, index, key):
+        """ Set up a new instance. """
+        self.__enumtype = enumtype
+        self.__index = index
+        self.__key = key
+
+    def __get_enumtype(self):
+        return self.__enumtype
+
+    enumtype = property(__get_enumtype)
+
+    def __get_key(self):
+        return self.__key
+
+    key = property(__get_key)
+
+    def __str__(self):
+        return "%s" % (self.key)
+
+    def __get_index(self):
+        return self.__index
+
+    index = property(__get_index)
+
+    def __repr__(self):
+        return "EnumValue(%s, %s, %s)" % (repr(self.__enumtype),
+                                          repr(self.__index),
+                                          repr(self.__key),)
+
+    def __hash__(self):
+        return hash(self.__index)
+
+    def __lt__(self, other):
+        """Less than operator
+
+        (Called in response to 'self < other' or 'other > self'.)
+        """
+        try:
+            return self.index < other.index
+        except Exception:
+            return NotImplemented
+
+    def __gt__(self, other):
+        """Greater than operator
+
+        (Called in response to 'self > other' or 'other < self'.)
+        """
+        try:
+            return self.index > other.index
+        except Exception:
+            return NotImplemented
+
+    def __le__(self, other):
+        """Less than or equal operator
+
+        (Called in response to 'self <= other' or 'other >= self'.)
+        """
+        try:
+            return self.index <= other.index
+        except Exception:
+            return NotImplemented
+
+    def __ge__(self, other):
+        """Greater than or equal operator
+
+        (Called in response to 'self >= other' or 'other <= self'.)
+        """
+        try:
+            return self.index >= other.index
+        except Exception:
+            return NotImplemented
+
+    def __eq__(self, other):
+        """Equal to operator
+
+        (Called in response to 'self == other'.)
+        """
+        try:
+            return self.index == other.index
+        except Exception:
+            return NotImplemented
+
+    def __ne__(self, other):
+        """Equal to operator
+
+        (Called in response to 'self != other'.)
+        """
+        try:
+            return self.index != other.index
+        except Exception:
+            return NotImplemented
+
+
+class Enum(object):
+    """ Enumerated type. """
+
+    def __init__(self, *keys, **kwargs):
+        """ Create an enumeration instance. """
+
+        if not keys:
+            raise EnumEmptyError()
+
+        keys = tuple(keys)
+        values = [None] * len(keys)
+
+        value_type = kwargs.get('value_type', EnumValue)
+
+        for i, key in enumerate(keys):
+            if isinstance(key, six.string_types):
+                value = value_type(self, i, key)
+            else:
+                if not isinstance(key, EnumValue):
+                    raise EnumBadKeyError(key)
+                value = key
+                key = value.key
+                if value.index != i:
+                    raise EnumBadIndexError(
+                        value.index, "Assigned index for argument with key %s, "
+                        "does not match location in the initialization list" %
+                        (key))
+            values[i] = value
+            if value.enumtype != values[0].enumtype:
+                raise EnumBadTypeError(
+                    value.enumtype,
+                    "Type assigned to positional argument %s (key=%s) "
+                    "does not match the type assigned to the first "
+                    "positional argument (key=%s): %r" %
+                    (i, key, values[0].key, values[0].enumtype))
+            try:
+                super(Enum, self).__setattr__(key, value)
+            except TypeError:
+                raise EnumBadKeyError(key)
+
+        super(Enum, self).__setattr__('_keys', keys)
+        super(Enum, self).__setattr__('_values', values)
+
+    def __call__(self, index):
+        #
+        # If the index is an integer, get the item
+        # with this index
+        #
+        if isinstance(index, int):
+            return self[index]
+        #
+        # If the index is not a string, then try coercing it
+        #
+        if not isinstance(index, six.string_types):
+            tmp = str(index)
+        else:
+            tmp = index
+        return getattr(self, tmp)
+
+    def __setattr__(self, name, value):
+        raise EnumImmutableError(name)
+
+    def __delattr__(self, name):
+        raise EnumImmutableError(name)
+
+    def __len__(self):
+        return len(self._values)
+
+    def __getitem__(self, index):
+        return self._values[index]
+
+    def __setitem__(self, index, value):
+        raise EnumImmutableError(index)
+
+    def __delitem__(self, index):
+        raise EnumImmutableError(index)
+
+    def __iter__(self):
+        return iter(self._values)
+
+    def __contains__(self, value):
+        is_member = False
+        if isinstance(value, six.string_types):
+            is_member = (value in self._keys)
+        else:
+            try:
+                is_member = (value in self._values)
+            except Exception:
+                is_member = False
+        return is_member

pyutilib/enum/tests/__init__.py

@@ -0,0 +1,9 @@
+#  _________________________________________________________________________
+#
+#  PyUtilib: A Python utility library.
+#  Copyright (c) 2008 Sandia Corporation.
+#  This software is distributed under the BSD License.
+#  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
+#  the U.S. Government retains certain rights in this software.
+#  _________________________________________________________________________
+#