Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/sqlalchemy/orm/evaluator.py: 31%

1# orm/evaluator.py 

2# Copyright (C) 2005-2024 the SQLAlchemy authors and contributors 

3# <see AUTHORS file> 

4# 

5# This module is part of SQLAlchemy and is released under 

6# the MIT License: https://www.opensource.org/licenses/mit-license.php 

7# mypy: ignore-errors 

8 

9"""Evaluation functions used **INTERNALLY** by ORM DML use cases. 

10 

11 

12This module is **private, for internal use by SQLAlchemy**. 

13 

14.. versionchanged:: 2.0.4 renamed ``EvaluatorCompiler`` to 

15 ``_EvaluatorCompiler``. 

16 

17""" 

18 

19 

20from __future__ import annotations 

21 

22from typing import Type 

23 

24from . import exc as orm_exc 

25from .base import LoaderCallableStatus 

26from .base import PassiveFlag 

27from .. import exc 

28from .. import inspect 

29from ..sql import and_ 

30from ..sql import operators 

31from ..sql.sqltypes import Integer 

32from ..sql.sqltypes import Numeric 

33from ..util import warn_deprecated 

34 

35 

36class UnevaluatableError(exc.InvalidRequestError): 

37 pass 

38 

39 

40class _NoObject(operators.ColumnOperators): 

41 def operate(self, *arg, **kw): 

42 return None 

43 

44 def reverse_operate(self, *arg, **kw): 

45 return None 

46 

47 

48class _ExpiredObject(operators.ColumnOperators): 

49 def operate(self, *arg, **kw): 

50 return self 

51 

52 def reverse_operate(self, *arg, **kw): 

53 return self 

54 

55 

56_NO_OBJECT = _NoObject() 

57_EXPIRED_OBJECT = _ExpiredObject() 

58 

59 

60class _EvaluatorCompiler: 

61 def __init__(self, target_cls=None): 

62 self.target_cls = target_cls 

63 

64 def process(self, clause, *clauses): 

65 if clauses: 

66 clause = and_(clause, *clauses) 

67 

68 meth = getattr(self, f"visit_{clause.__visit_name__}", None) 

69 if not meth: 

70 raise UnevaluatableError( 

71 f"Cannot evaluate {type(clause).__name__}" 

72 ) 

73 return meth(clause) 

74 

75 def visit_grouping(self, clause): 

76 return self.process(clause.element) 

77 

78 def visit_null(self, clause): 

79 return lambda obj: None 

80 

81 def visit_false(self, clause): 

82 return lambda obj: False 

83 

84 def visit_true(self, clause): 

85 return lambda obj: True 

86 

87 def visit_column(self, clause): 

88 try: 

89 parentmapper = clause._annotations["parentmapper"] 

90 except KeyError as ke: 

91 raise UnevaluatableError( 

92 f"Cannot evaluate column: {clause}" 

93 ) from ke 

94 

95 if self.target_cls and not issubclass( 

96 self.target_cls, parentmapper.class_ 

97 ): 

98 raise UnevaluatableError( 

99 "Can't evaluate criteria against " 

100 f"alternate class {parentmapper.class_}" 

101 ) 

102 

103 parentmapper._check_configure() 

104 

105 # we'd like to use "proxy_key" annotation to get the "key", however 

106 # in relationship primaryjoin cases proxy_key is sometimes deannotated 

107 # and sometimes apparently not present in the first place (?). 

108 # While I can stop it from being deannotated (though need to see if 

109 # this breaks other things), not sure right now about cases where it's 

110 # not there in the first place. can fix at some later point. 

111 # key = clause._annotations["proxy_key"] 

112 

113 # for now, use the old way 

114 try: 

115 key = parentmapper._columntoproperty[clause].key 

116 except orm_exc.UnmappedColumnError as err: 

117 raise UnevaluatableError( 

118 f"Cannot evaluate expression: {err}" 

119 ) from err 

120 

121 # note this used to fall back to a simple `getattr(obj, key)` evaluator 

122 # if impl was None; as of #8656, we ensure mappers are configured 

123 # so that impl is available 

124 impl = parentmapper.class_manager[key].impl 

125 

126 def get_corresponding_attr(obj): 

127 if obj is None: 

128 return _NO_OBJECT 

129 state = inspect(obj) 

130 dict_ = state.dict 

131 

132 value = impl.get( 

133 state, dict_, passive=PassiveFlag.PASSIVE_NO_FETCH 

134 ) 

135 if value is LoaderCallableStatus.PASSIVE_NO_RESULT: 

136 return _EXPIRED_OBJECT 

137 return value 

138 

139 return get_corresponding_attr 

140 

141 def visit_tuple(self, clause): 

142 return self.visit_clauselist(clause) 

143 

144 def visit_expression_clauselist(self, clause): 

145 return self.visit_clauselist(clause) 

146 

147 def visit_clauselist(self, clause): 

148 evaluators = [self.process(clause) for clause in clause.clauses] 

149 

150 dispatch = ( 

151 f"visit_{clause.operator.__name__.rstrip('_')}_clauselist_op" 

152 ) 

153 meth = getattr(self, dispatch, None) 

154 if meth: 

155 return meth(clause.operator, evaluators, clause) 

156 else: 

157 raise UnevaluatableError( 

158 f"Cannot evaluate clauselist with operator {clause.operator}" 

159 ) 

160 

161 def visit_binary(self, clause): 

162 eval_left = self.process(clause.left) 

163 eval_right = self.process(clause.right) 

164 

165 dispatch = f"visit_{clause.operator.__name__.rstrip('_')}_binary_op" 

166 meth = getattr(self, dispatch, None) 

167 if meth: 

168 return meth(clause.operator, eval_left, eval_right, clause) 

169 else: 

170 raise UnevaluatableError( 

171 f"Cannot evaluate {type(clause).__name__} with " 

172 f"operator {clause.operator}" 

173 ) 

174 

175 def visit_or_clauselist_op(self, operator, evaluators, clause): 

176 def evaluate(obj): 

177 has_null = False 

178 for sub_evaluate in evaluators: 

179 value = sub_evaluate(obj) 

180 if value is _EXPIRED_OBJECT: 

181 return _EXPIRED_OBJECT 

182 elif value: 

183 return True 

184 has_null = has_null or value is None 

185 if has_null: 

186 return None 

187 return False 

188 

189 return evaluate 

190 

191 def visit_and_clauselist_op(self, operator, evaluators, clause): 

192 def evaluate(obj): 

193 for sub_evaluate in evaluators: 

194 value = sub_evaluate(obj) 

195 if value is _EXPIRED_OBJECT: 

196 return _EXPIRED_OBJECT 

197 

198 if not value: 

199 if value is None or value is _NO_OBJECT: 

200 return None 

201 return False 

202 return True 

203 

204 return evaluate 

205 

206 def visit_comma_op_clauselist_op(self, operator, evaluators, clause): 

207 def evaluate(obj): 

208 values = [] 

209 for sub_evaluate in evaluators: 

210 value = sub_evaluate(obj) 

211 if value is _EXPIRED_OBJECT: 

212 return _EXPIRED_OBJECT 

213 elif value is None or value is _NO_OBJECT: 

214 return None 

215 values.append(value) 

216 return tuple(values) 

217 

218 return evaluate 

219 

220 def visit_custom_op_binary_op( 

221 self, operator, eval_left, eval_right, clause 

222 ): 

223 if operator.python_impl: 

224 return self._straight_evaluate( 

225 operator, eval_left, eval_right, clause 

226 ) 

227 else: 

228 raise UnevaluatableError( 

229 f"Custom operator {operator.opstring!r} can't be evaluated " 

230 "in Python unless it specifies a callable using " 

231 "`.python_impl`." 

232 ) 

233 

234 def visit_is_binary_op(self, operator, eval_left, eval_right, clause): 

235 def evaluate(obj): 

236 left_val = eval_left(obj) 

237 right_val = eval_right(obj) 

238 if left_val is _EXPIRED_OBJECT or right_val is _EXPIRED_OBJECT: 

239 return _EXPIRED_OBJECT 

240 return left_val == right_val 

241 

242 return evaluate 

243 

244 def visit_is_not_binary_op(self, operator, eval_left, eval_right, clause): 

245 def evaluate(obj): 

246 left_val = eval_left(obj) 

247 right_val = eval_right(obj) 

248 if left_val is _EXPIRED_OBJECT or right_val is _EXPIRED_OBJECT: 

249 return _EXPIRED_OBJECT 

250 return left_val != right_val 

251 

252 return evaluate 

253 

254 def _straight_evaluate(self, operator, eval_left, eval_right, clause): 

255 def evaluate(obj): 

256 left_val = eval_left(obj) 

257 right_val = eval_right(obj) 

258 if left_val is _EXPIRED_OBJECT or right_val is _EXPIRED_OBJECT: 

259 return _EXPIRED_OBJECT 

260 elif left_val is None or right_val is None: 

261 return None 

262 

263 return operator(eval_left(obj), eval_right(obj)) 

264 

265 return evaluate 

266 

267 def _straight_evaluate_numeric_only( 

268 self, operator, eval_left, eval_right, clause 

269 ): 

270 if clause.left.type._type_affinity not in ( 

271 Numeric, 

272 Integer, 

273 ) or clause.right.type._type_affinity not in (Numeric, Integer): 

274 raise UnevaluatableError( 

275 f'Cannot evaluate math operator "{operator.__name__}" for ' 

276 f"datatypes {clause.left.type}, {clause.right.type}" 

277 ) 

278 

279 return self._straight_evaluate(operator, eval_left, eval_right, clause) 

280 

281 visit_add_binary_op = _straight_evaluate_numeric_only 

282 visit_mul_binary_op = _straight_evaluate_numeric_only 

283 visit_sub_binary_op = _straight_evaluate_numeric_only 

284 visit_mod_binary_op = _straight_evaluate_numeric_only 

285 visit_truediv_binary_op = _straight_evaluate_numeric_only 

286 visit_lt_binary_op = _straight_evaluate 

287 visit_le_binary_op = _straight_evaluate 

288 visit_ne_binary_op = _straight_evaluate 

289 visit_gt_binary_op = _straight_evaluate 

290 visit_ge_binary_op = _straight_evaluate 

291 visit_eq_binary_op = _straight_evaluate 

292 

293 def visit_in_op_binary_op(self, operator, eval_left, eval_right, clause): 

294 return self._straight_evaluate( 

295 lambda a, b: a in b if a is not _NO_OBJECT else None, 

296 eval_left, 

297 eval_right, 

298 clause, 

299 ) 

300 

301 def visit_not_in_op_binary_op( 

302 self, operator, eval_left, eval_right, clause 

303 ): 

304 return self._straight_evaluate( 

305 lambda a, b: a not in b if a is not _NO_OBJECT else None, 

306 eval_left, 

307 eval_right, 

308 clause, 

309 ) 

310 

311 def visit_concat_op_binary_op( 

312 self, operator, eval_left, eval_right, clause 

313 ): 

314 return self._straight_evaluate( 

315 lambda a, b: a + b, eval_left, eval_right, clause 

316 ) 

317 

318 def visit_startswith_op_binary_op( 

319 self, operator, eval_left, eval_right, clause 

320 ): 

321 return self._straight_evaluate( 

322 lambda a, b: a.startswith(b), eval_left, eval_right, clause 

323 ) 

324 

325 def visit_endswith_op_binary_op( 

326 self, operator, eval_left, eval_right, clause 

327 ): 

328 return self._straight_evaluate( 

329 lambda a, b: a.endswith(b), eval_left, eval_right, clause 

330 ) 

331 

332 def visit_unary(self, clause): 

333 eval_inner = self.process(clause.element) 

334 if clause.operator is operators.inv: 

335 

336 def evaluate(obj): 

337 value = eval_inner(obj) 

338 if value is _EXPIRED_OBJECT: 

339 return _EXPIRED_OBJECT 

340 elif value is None: 

341 return None 

342 return not value 

343 

344 return evaluate 

345 raise UnevaluatableError( 

346 f"Cannot evaluate {type(clause).__name__} " 

347 f"with operator {clause.operator}" 

348 ) 

349 

350 def visit_bindparam(self, clause): 

351 if clause.callable: 

352 val = clause.callable() 

353 else: 

354 val = clause.value 

355 return lambda obj: val 

356 

357 

358def __getattr__(name: str) -> Type[_EvaluatorCompiler]: 

359 if name == "EvaluatorCompiler": 

360 warn_deprecated( 

361 "Direct use of 'EvaluatorCompiler' is not supported, and this " 

362 "name will be removed in a future release. " 

363 "'_EvaluatorCompiler' is for internal use only", 

364 "2.0", 

365 ) 

366 return _EvaluatorCompiler 

367 else: 

368 raise AttributeError(f"module {__name__!r} has no attribute {name!r}")