Datasets:
File size: 8,009 Bytes
d8a7ddd | 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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 | """
Tests the basic definition rules for protocols.
"""
# Specification: https://typing.readthedocs.io/en/latest/spec/protocol.html#defining-a-protocol
from abc import abstractmethod
from typing import Any, ClassVar, Iterable, NamedTuple, Protocol, Sequence
from dataclasses import dataclass
class SupportsClose(Protocol):
def close(self) -> None:
...
class Resource:
def close(self) -> None:
pass
def close_all(things: Iterable[SupportsClose]) -> None:
for t in things:
t.close()
f = open("foo.txt")
r = Resource()
close_all([f, r]) # OK
close_all([1]) # E: 'int' has no 'close' method
class Example(Protocol):
def first(self) -> int: # This is a protocol member
return 42
@abstractmethod
def second(self) -> int: # Method without a default implementation
raise NotImplementedError
# > Static methods, class methods, and properties are equally allowed in protocols.
@staticmethod
def third() -> int:
...
@classmethod
def fourth(cls) -> int:
...
@property
def fifth(self) -> int:
...
# > To define a protocol variable, one can use PEP 526 variable annotations
# > in the class body. Additional attributes only defined in the body of a
# > method by assignment via self are not allowed.
class Template(Protocol):
name: str # This is a protocol member
value: int = 0 # This one too (with default)
def method(self) -> None:
self.name = "name" # OK
self.temp: list[int] = [] # E: use of self variables not allowed
class Concrete:
def __init__(self, name: str, value: int) -> None:
self.name = name
self.value = value
def method(self) -> None:
return
var: Template = Concrete("value", 42) # OK
# > To distinguish between protocol class variables and protocol instance
# > variables, the special ClassVar annotation should be used as specified
# > by PEP 526. By default, protocol variables as defined above are considered
# > readable and writable. To define a read-only protocol variable, one can
# > use an (abstract) property.
class Template2(Protocol):
val1: ClassVar[Sequence[int]]
class Concrete2_Good1:
val1: ClassVar[Sequence[int]] = [2]
class Concrete2_Bad1:
...
class Concrete2_Bad2:
val1: Sequence[float] = [2]
class Concrete2_Bad3:
val1: list[int] = [2]
class Concrete2_Bad4:
val1: Sequence[int] = [2]
v2_good1: Template2 = Concrete2_Good1() # OK
v2_bad1: Template2 = Concrete2_Bad1() # E
v2_bad2: Template2 = Concrete2_Bad2() # E
v2_bad3: Template2 = Concrete2_Bad3() # E
v2_bad4: Template2 = Concrete2_Bad4() # E?: Explicit ClassVar matching is unspecified
class Template3(Protocol):
val1: Sequence[int]
class Concrete3_Good1:
val1: Sequence[int] = [0]
class Concrete3_Good2:
def __init__(self) -> None:
self.val1: Sequence[int] = [0]
class Concrete3_Bad1:
...
class Concrete3_Bad2:
val1: ClassVar[Sequence[int]] = [0]
class Concrete3_Bad3:
@property
def val1(self) -> Sequence[int]:
return [0]
class Concrete3_Bad4:
val1: Sequence[float] = [0]
class Concrete3_Bad5:
val1: list[int] = [0]
v3_good1: Template3 = Concrete3_Good1() # OK
v3_bad1: Template3 = Concrete3_Bad1() # E
v3_bad2: Template3 = Concrete3_Bad2() # E
v3_bad3: Template3 = Concrete3_Bad3() # E
v3_bad4: Template3 = Concrete3_Bad4() # E
v3_bad5: Template3 = Concrete3_Bad5() # E
class Template4(Protocol):
@property
def val1(self) -> Sequence[float]:
...
class Concrete4_Good1:
@property
def val1(self) -> Sequence[float]:
return [0]
class Concrete4_Good2:
@property
def val1(self) -> Sequence[int]:
return [0]
class Concrete4_Good3:
val1: Sequence[float] = [0]
class Concrete4_Good4:
val1: Sequence[int] = [0]
class Concrete4_Good5:
val1: list[float] = [0]
class Concrete4_Good6(NamedTuple):
val1: Sequence[float] = [0]
@dataclass(frozen=False)
class Concrete4_Good7:
val1: Sequence[float] = (0,)
class Concrete4_Bad1:
def val1(self) -> Sequence[int]: # Not a property
return [0]
class Concrete4_Bad2:
...
v4_good1: Template4 = Concrete4_Good1() # OK
v4_good2: Template4 = Concrete4_Good2() # OK
v4_good3: Template4 = Concrete4_Good3() # OK
v4_good4: Template4 = Concrete4_Good4() # OK
v4_good5: Template4 = Concrete4_Good5() # OK
v4_good6: Template4 = Concrete4_Good6() # OK
v4_good7: Template4 = Concrete4_Good7() # OK
v4_bad1: Template4 = Concrete4_Bad1() # E
v4_bad2: Template4 = Concrete4_Bad2() # E
class Template5(Protocol):
def method1(self, a: int, b: int) -> float:
...
class Concrete5_Good1:
def method1(self, a: float, b: float) -> int:
return 0
class Concrete5_Good2:
def method1(self, *args: float, **kwargs: float) -> Any:
return 0.0
class Concrete5_Good3:
def method1(self, a, b) -> Any:
return 0.0
class Concrete5_Good4:
@classmethod
def method1(cls, a: int, b: int) -> float:
return 0
class Concrete5_Good5:
@staticmethod
def method1(a: int, b: int) -> float:
return 0
class Concrete5_Bad1:
def method1(self, a, c) -> int:
return 0
class Concrete5_Bad2:
def method1(self, a: int, c: int) -> int:
return 0
class Concrete5_Bad3:
def method1(self, *, a: int, b: int) -> float:
return 0
class Concrete5_Bad4:
def method1(self, a: int, b: int, /) -> float:
return 0
class Concrete5_Bad5:
@staticmethod
def method1(self, a: int, b: int) -> float:
return 0
v5_good1: Template5 = Concrete5_Good1() # OK
v5_good2: Template5 = Concrete5_Good2() # OK
v5_good3: Template5 = Concrete5_Good3() # OK
v5_good4: Template5 = Concrete5_Good4() # OK
v5_good5: Template5 = Concrete5_Good5() # OK
v5_bad1: Template5 = Concrete5_Bad1() # E
v5_bad2: Template5 = Concrete5_Bad2() # E
v5_bad3: Template5 = Concrete5_Bad3() # E
v5_bad4: Template5 = Concrete5_Bad4() # E
v5_bad5: Template5 = Concrete5_Bad5() # E
class Template6(Protocol):
@property
def val1(self) -> Sequence[float]:
...
@val1.setter
def val1(self, val: Sequence[float]) -> None:
...
class Concrete6_Good1:
@property
def val1(self) -> Sequence[float]:
return [0]
@val1.setter
def val1(self, val: Sequence[float]) -> None:
pass
class Concrete6_Good2:
val1: Sequence[float] = [0]
@dataclass(frozen=False)
class Concrete6_Good3:
val1: Sequence[float] = (0,)
class Concrete6_Bad1:
@property
def val1(self) -> Sequence[float]:
return [0]
class Concrete6_Bad2(NamedTuple):
val1: Sequence[float] = [0]
@dataclass(frozen=True)
class Concrete6_Bad3:
val1: Sequence[float] = (0,)
v6_good1: Template6 = Concrete6_Good1() # OK
v6_good2: Template6 = Concrete6_Good2() # OK
v6_good3: Template6 = Concrete6_Good3() # OK
v6_bad1: Template6 = Concrete6_Bad1() # E
v6_bad2: Template6 = Concrete6_Bad2() # E: named tuple is immutable
v6_bad3: Template6 = Concrete6_Bad3() # E: dataclass is frozen
# The specification leaves two possible interpretations of a ClassVar protocol
# member. One interpretation requires the implementing attribute to be explicitly
# declared with ClassVar. The other interpretation imposes only structural
# requirements: the attribute must be readable and writable on the class object
# and readable on instances of the class. Both interpretations therefore require
# the following assignments to be rejected.
class Template7(Protocol):
val1: ClassVar[int]
class Concrete7_Bad1:
def __init__(self) -> None:
self.val1: int = 42
class Concrete7Meta(type):
val1: int = 42
class Concrete7_Bad2(metaclass=Concrete7Meta):
pass
v7_bad1: Template7 = Concrete7_Bad1() # E: val1 is not readable on the class object
v7_bad2: Template7 = Concrete7_Bad2() # E: val1 is not readable on instances
|