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
|
"""Symbolic global constants, like 'None', 'NOT_FOUND', etc."""
__all__ = [
'Symbol','NOT_GIVEN','NOT_FOUND'
]
class Symbol(object):
"""Symbolic global constant"""
__slots__ = ['_name', '_module']
__name__ = property(lambda s: s._name)
__module__ = property(lambda s: s._module)
def __init__(self, symbol, moduleName):
self.__class__._name.__set__(self,symbol)
self.__class__._module.__set__(self,moduleName)
def __reduce__(self):
return self._name
def __setattr__(self,attr,val):
raise TypeError("Symbols are immutable")
def __repr__(self):
return self.__name__
__str__ = __repr__
NOT_GIVEN = Symbol("NOT_GIVEN", __name__)
NOT_FOUND = Symbol("NOT_FOUND", __name__)
|
