-
Notifications
You must be signed in to change notification settings - Fork 0
/
enum.py
executable file
·193 lines (146 loc) · 5.37 KB
/
enum.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
# -*- 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.
"""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
"""
__author_name__ = "Ben Finney"
__author_email__ = "ben+python@benfinney.id.au"
__author__ = "%s <%s>" % (__author_name__, __author_email__)
__date__ = "2007-01-24"
__copyright__ = "Copyright © %s %s" % (
__date__.split('-')[0], __author_name__
)
__license__ = "Choice of GPL or Python license"
__url__ = "http://cheeseshop.python.org/pypi/enum/"
__version__ = "0.4.3"
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: %s" % (self.key,)
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 __cmp__(self, other):
result = NotImplemented
self_type = self.enumtype
try:
assert self_type == other.enumtype
result = cmp(self.index, other.index)
except (AssertionError, AttributeError):
result = NotImplemented
return result
class Enum(object):
""" Enumerated type """
def __init__(self, *keys, **kwargs):
""" Create an enumeration instance """
value_type = kwargs.get('value_type', EnumValue)
if not keys:
raise EnumEmptyError()
keys = tuple(keys)
values = [None] * len(keys)
for i, key in enumerate(keys):
value = value_type(self, i, key)
values[i] = value
try:
super(Enum, self).__setattr__(key, value)
except TypeError, e:
raise EnumBadKeyError(key)
super(Enum, self).__setattr__('_keys', keys)
super(Enum, self).__setattr__('_values', values)
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, basestring):
is_member = (value in self._keys)
else:
try:
is_member = (value in self._values)
except EnumValueCompareError, e:
is_member = False
return is_member