blob: 8b0a751ad5517e2bca3e43c8aeea1144d3558d7d (
plain)
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
|
# sqlalchemy/inspect.py
# Copyright (C) 2005-2012 the SQLAlchemy authors and contributors <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
"""Base inspect API.
:func:`.inspect` provides access to a contextual object
regarding a subject.
Various subsections of SQLAlchemy,
such as the :class:`.Inspector`, :class:`.Mapper`, and
others register themselves with the "inspection registry" here
so that they may return a context object given a certain kind
of argument.
"""
from . import util, exc
_registrars = util.defaultdict(list)
def inspect(subject, raiseerr=True):
type_ = type(subject)
for cls in type_.__mro__:
if cls in _registrars:
reg = _registrars[cls]
ret = reg(subject)
if ret is not None:
break
else:
reg = ret = None
if raiseerr and (
reg is None or ret is None
):
raise exc.NoInspectionAvailable(
"No inspection system is "
"available for object of type %s" %
type_)
return ret
def _inspects(*types):
def decorate(fn_or_cls):
for type_ in types:
if type_ in _registrars:
raise AssertionError(
"Type %s is already "
"registered" % type_)
_registrars[type_] = fn_or_cls
return fn_or_cls
return decorate
def _self_inspects(*types):
_inspects(*types)(lambda subject:subject)
|
