Spaces:
Sleeping
Sleeping
File size: 87,149 Bytes
69d9940 |
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 |
import abc
import collections
import collections.abc
import operator
import sys
import typing
# After PEP 560, internal typing API was substantially reworked.
# This is especially important for Protocol class which uses internal APIs
# quite extensively.
PEP_560 = sys.version_info[:3] >= (3, 7, 0)
if PEP_560:
GenericMeta = type
else:
# 3.6
from typing import GenericMeta, _type_vars # noqa
# The two functions below are copies of typing internal helpers.
# They are needed by _ProtocolMeta
def _no_slots_copy(dct):
dict_copy = dict(dct)
if '__slots__' in dict_copy:
for slot in dict_copy['__slots__']:
dict_copy.pop(slot, None)
return dict_copy
def _check_generic(cls, parameters):
if not cls.__parameters__:
raise TypeError(f"{cls} is not a generic class")
alen = len(parameters)
elen = len(cls.__parameters__)
if alen != elen:
raise TypeError(f"Too {'many' if alen > elen else 'few'} arguments for {cls};"
f" actual {alen}, expected {elen}")
# Please keep __all__ alphabetized within each category.
__all__ = [
# Super-special typing primitives.
'ClassVar',
'Concatenate',
'Final',
'ParamSpec',
'Self',
'Type',
# ABCs (from collections.abc).
'Awaitable',
'AsyncIterator',
'AsyncIterable',
'Coroutine',
'AsyncGenerator',
'AsyncContextManager',
'ChainMap',
# Concrete collection types.
'ContextManager',
'Counter',
'Deque',
'DefaultDict',
'OrderedDict',
'TypedDict',
# Structural checks, a.k.a. protocols.
'SupportsIndex',
# One-off things.
'Annotated',
'final',
'IntVar',
'Literal',
'NewType',
'overload',
'Protocol',
'runtime',
'runtime_checkable',
'Text',
'TypeAlias',
'TypeGuard',
'TYPE_CHECKING',
]
if PEP_560:
__all__.extend(["get_args", "get_origin", "get_type_hints"])
# 3.6.2+
if hasattr(typing, 'NoReturn'):
NoReturn = typing.NoReturn
# 3.6.0-3.6.1
else:
class _NoReturn(typing._FinalTypingBase, _root=True):
"""Special type indicating functions that never return.
Example::
from typing import NoReturn
def stop() -> NoReturn:
raise Exception('no way')
This type is invalid in other positions, e.g., ``List[NoReturn]``
will fail in static type checkers.
"""
__slots__ = ()
def __instancecheck__(self, obj):
raise TypeError("NoReturn cannot be used with isinstance().")
def __subclasscheck__(self, cls):
raise TypeError("NoReturn cannot be used with issubclass().")
NoReturn = _NoReturn(_root=True)
# Some unconstrained type variables. These are used by the container types.
# (These are not for export.)
T = typing.TypeVar('T') # Any type.
KT = typing.TypeVar('KT') # Key type.
VT = typing.TypeVar('VT') # Value type.
T_co = typing.TypeVar('T_co', covariant=True) # Any type covariant containers.
T_contra = typing.TypeVar('T_contra', contravariant=True) # Ditto contravariant.
ClassVar = typing.ClassVar
# On older versions of typing there is an internal class named "Final".
# 3.8+
if hasattr(typing, 'Final') and sys.version_info[:2] >= (3, 7):
Final = typing.Final
# 3.7
elif sys.version_info[:2] >= (3, 7):
class _FinalForm(typing._SpecialForm, _root=True):
def __repr__(self):
return 'typing_extensions.' + self._name
def __getitem__(self, parameters):
item = typing._type_check(parameters,
f'{self._name} accepts only single type')
return typing._GenericAlias(self, (item,))
Final = _FinalForm('Final',
doc="""A special typing construct to indicate that a name
cannot be re-assigned or overridden in a subclass.
For example:
MAX_SIZE: Final = 9000
MAX_SIZE += 1 # Error reported by type checker
class Connection:
TIMEOUT: Final[int] = 10
class FastConnector(Connection):
TIMEOUT = 1 # Error reported by type checker
There is no runtime checking of these properties.""")
# 3.6
else:
class _Final(typing._FinalTypingBase, _root=True):
"""A special typing construct to indicate that a name
cannot be re-assigned or overridden in a subclass.
For example:
MAX_SIZE: Final = 9000
MAX_SIZE += 1 # Error reported by type checker
class Connection:
TIMEOUT: Final[int] = 10
class FastConnector(Connection):
TIMEOUT = 1 # Error reported by type checker
There is no runtime checking of these properties.
"""
__slots__ = ('__type__',)
def __init__(self, tp=None, **kwds):
self.__type__ = tp
def __getitem__(self, item):
cls = type(self)
if self.__type__ is None:
return cls(typing._type_check(item,
f'{cls.__name__[1:]} accepts only single type.'),
_root=True)
raise TypeError(f'{cls.__name__[1:]} cannot be further subscripted')
def _eval_type(self, globalns, localns):
new_tp = typing._eval_type(self.__type__, globalns, localns)
if new_tp == self.__type__:
return self
return type(self)(new_tp, _root=True)
def __repr__(self):
r = super().__repr__()
if self.__type__ is not None:
r += f'[{typing._type_repr(self.__type__)}]'
return r
def __hash__(self):
return hash((type(self).__name__, self.__type__))
def __eq__(self, other):
if not isinstance(other, _Final):
return NotImplemented
if self.__type__ is not None:
return self.__type__ == other.__type__
return self is other
Final = _Final(_root=True)
# 3.8+
if hasattr(typing, 'final'):
final = typing.final
# 3.6-3.7
else:
def final(f):
"""This decorator can be used to indicate to type checkers that
the decorated method cannot be overridden, and decorated class
cannot be subclassed. For example:
class Base:
@final
def done(self) -> None:
...
class Sub(Base):
def done(self) -> None: # Error reported by type checker
...
@final
class Leaf:
...
class Other(Leaf): # Error reported by type checker
...
There is no runtime checking of these properties.
"""
return f
def IntVar(name):
return typing.TypeVar(name)
# 3.8+:
if hasattr(typing, 'Literal'):
Literal = typing.Literal
# 3.7:
elif sys.version_info[:2] >= (3, 7):
class _LiteralForm(typing._SpecialForm, _root=True):
def __repr__(self):
return 'typing_extensions.' + self._name
def __getitem__(self, parameters):
return typing._GenericAlias(self, parameters)
Literal = _LiteralForm('Literal',
doc="""A type that can be used to indicate to type checkers
that the corresponding value has a value literally equivalent
to the provided parameter. For example:
var: Literal[4] = 4
The type checker understands that 'var' is literally equal to
the value 4 and no other value.
Literal[...] cannot be subclassed. There is no runtime
checking verifying that the parameter is actually a value
instead of a type.""")
# 3.6:
else:
class _Literal(typing._FinalTypingBase, _root=True):
"""A type that can be used to indicate to type checkers that the
corresponding value has a value literally equivalent to the
provided parameter. For example:
var: Literal[4] = 4
The type checker understands that 'var' is literally equal to the
value 4 and no other value.
Literal[...] cannot be subclassed. There is no runtime checking
verifying that the parameter is actually a value instead of a type.
"""
__slots__ = ('__values__',)
def __init__(self, values=None, **kwds):
self.__values__ = values
def __getitem__(self, values):
cls = type(self)
if self.__values__ is None:
if not isinstance(values, tuple):
values = (values,)
return cls(values, _root=True)
raise TypeError(f'{cls.__name__[1:]} cannot be further subscripted')
def _eval_type(self, globalns, localns):
return self
def __repr__(self):
r = super().__repr__()
if self.__values__ is not None:
r += f'[{", ".join(map(typing._type_repr, self.__values__))}]'
return r
def __hash__(self):
return hash((type(self).__name__, self.__values__))
def __eq__(self, other):
if not isinstance(other, _Literal):
return NotImplemented
if self.__values__ is not None:
return self.__values__ == other.__values__
return self is other
Literal = _Literal(_root=True)
_overload_dummy = typing._overload_dummy # noqa
overload = typing.overload
# This is not a real generic class. Don't use outside annotations.
Type = typing.Type
# Various ABCs mimicking those in collections.abc.
# A few are simply re-exported for completeness.
class _ExtensionsGenericMeta(GenericMeta):
def __subclasscheck__(self, subclass):
"""This mimics a more modern GenericMeta.__subclasscheck__() logic
(that does not have problems with recursion) to work around interactions
between collections, typing, and typing_extensions on older
versions of Python, see https://github.com/python/typing/issues/501.
"""
if self.__origin__ is not None:
if sys._getframe(1).f_globals['__name__'] not in ['abc', 'functools']:
raise TypeError("Parameterized generics cannot be used with class "
"or instance checks")
return False
if not self.__extra__:
return super().__subclasscheck__(subclass)
res = self.__extra__.__subclasshook__(subclass)
if res is not NotImplemented:
return res
if self.__extra__ in subclass.__mro__:
return True
for scls in self.__extra__.__subclasses__():
if isinstance(scls, GenericMeta):
continue
if issubclass(subclass, scls):
return True
return False
Awaitable = typing.Awaitable
Coroutine = typing.Coroutine
AsyncIterable = typing.AsyncIterable
AsyncIterator = typing.AsyncIterator
# 3.6.1+
if hasattr(typing, 'Deque'):
Deque = typing.Deque
# 3.6.0
else:
class Deque(collections.deque, typing.MutableSequence[T],
metaclass=_ExtensionsGenericMeta,
extra=collections.deque):
__slots__ = ()
def __new__(cls, *args, **kwds):
if cls._gorg is Deque:
return collections.deque(*args, **kwds)
return typing._generic_new(collections.deque, cls, *args, **kwds)
ContextManager = typing.ContextManager
# 3.6.2+
if hasattr(typing, 'AsyncContextManager'):
AsyncContextManager = typing.AsyncContextManager
# 3.6.0-3.6.1
else:
from _collections_abc import _check_methods as _check_methods_in_mro # noqa
class AsyncContextManager(typing.Generic[T_co]):
__slots__ = ()
async def __aenter__(self):
return self
@abc.abstractmethod
async def __aexit__(self, exc_type, exc_value, traceback):
return None
@classmethod
def __subclasshook__(cls, C):
if cls is AsyncContextManager:
return _check_methods_in_mro(C, "__aenter__", "__aexit__")
return NotImplemented
DefaultDict = typing.DefaultDict
# 3.7.2+
if hasattr(typing, 'OrderedDict'):
OrderedDict = typing.OrderedDict
# 3.7.0-3.7.2
elif (3, 7, 0) <= sys.version_info[:3] < (3, 7, 2):
OrderedDict = typing._alias(collections.OrderedDict, (KT, VT))
# 3.6
else:
class OrderedDict(collections.OrderedDict, typing.MutableMapping[KT, VT],
metaclass=_ExtensionsGenericMeta,
extra=collections.OrderedDict):
__slots__ = ()
def __new__(cls, *args, **kwds):
if cls._gorg is OrderedDict:
return collections.OrderedDict(*args, **kwds)
return typing._generic_new(collections.OrderedDict, cls, *args, **kwds)
# 3.6.2+
if hasattr(typing, 'Counter'):
Counter = typing.Counter
# 3.6.0-3.6.1
else:
class Counter(collections.Counter,
typing.Dict[T, int],
metaclass=_ExtensionsGenericMeta, extra=collections.Counter):
__slots__ = ()
def __new__(cls, *args, **kwds):
if cls._gorg is Counter:
return collections.Counter(*args, **kwds)
return typing._generic_new(collections.Counter, cls, *args, **kwds)
# 3.6.1+
if hasattr(typing, 'ChainMap'):
ChainMap = typing.ChainMap
elif hasattr(collections, 'ChainMap'):
class ChainMap(collections.ChainMap, typing.MutableMapping[KT, VT],
metaclass=_ExtensionsGenericMeta,
extra=collections.ChainMap):
__slots__ = ()
def __new__(cls, *args, **kwds):
if cls._gorg is ChainMap:
return collections.ChainMap(*args, **kwds)
return typing._generic_new(collections.ChainMap, cls, *args, **kwds)
# 3.6.1+
if hasattr(typing, 'AsyncGenerator'):
AsyncGenerator = typing.AsyncGenerator
# 3.6.0
else:
class AsyncGenerator(AsyncIterator[T_co], typing.Generic[T_co, T_contra],
metaclass=_ExtensionsGenericMeta,
extra=collections.abc.AsyncGenerator):
__slots__ = ()
NewType = typing.NewType
Text = typing.Text
TYPE_CHECKING = typing.TYPE_CHECKING
def _gorg(cls):
"""This function exists for compatibility with old typing versions."""
assert isinstance(cls, GenericMeta)
if hasattr(cls, '_gorg'):
return cls._gorg
while cls.__origin__ is not None:
cls = cls.__origin__
return cls
_PROTO_WHITELIST = ['Callable', 'Awaitable',
'Iterable', 'Iterator', 'AsyncIterable', 'AsyncIterator',
'Hashable', 'Sized', 'Container', 'Collection', 'Reversible',
'ContextManager', 'AsyncContextManager']
def _get_protocol_attrs(cls):
attrs = set()
for base in cls.__mro__[:-1]: # without object
if base.__name__ in ('Protocol', 'Generic'):
continue
annotations = getattr(base, '__annotations__', {})
for attr in list(base.__dict__.keys()) + list(annotations.keys()):
if (not attr.startswith('_abc_') and attr not in (
'__abstractmethods__', '__annotations__', '__weakref__',
'_is_protocol', '_is_runtime_protocol', '__dict__',
'__args__', '__slots__',
'__next_in_mro__', '__parameters__', '__origin__',
'__orig_bases__', '__extra__', '__tree_hash__',
'__doc__', '__subclasshook__', '__init__', '__new__',
'__module__', '_MutableMapping__marker', '_gorg')):
attrs.add(attr)
return attrs
def _is_callable_members_only(cls):
return all(callable(getattr(cls, attr, None)) for attr in _get_protocol_attrs(cls))
# 3.8+
if hasattr(typing, 'Protocol'):
Protocol = typing.Protocol
# 3.7
elif PEP_560:
from typing import _collect_type_vars # noqa
def _no_init(self, *args, **kwargs):
if type(self)._is_protocol:
raise TypeError('Protocols cannot be instantiated')
class _ProtocolMeta(abc.ABCMeta):
# This metaclass is a bit unfortunate and exists only because of the lack
# of __instancehook__.
def __instancecheck__(cls, instance):
# We need this method for situations where attributes are
# assigned in __init__.
if ((not getattr(cls, '_is_protocol', False) or
_is_callable_members_only(cls)) and
issubclass(instance.__class__, cls)):
return True
if cls._is_protocol:
if all(hasattr(instance, attr) and
(not callable(getattr(cls, attr, None)) or
getattr(instance, attr) is not None)
for attr in _get_protocol_attrs(cls)):
return True
return super().__instancecheck__(instance)
class Protocol(metaclass=_ProtocolMeta):
# There is quite a lot of overlapping code with typing.Generic.
# Unfortunately it is hard to avoid this while these live in two different
# modules. The duplicated code will be removed when Protocol is moved to typing.
"""Base class for protocol classes. Protocol classes are defined as::
class Proto(Protocol):
def meth(self) -> int:
...
Such classes are primarily used with static type checkers that recognize
structural subtyping (static duck-typing), for example::
class C:
def meth(self) -> int:
return 0
def func(x: Proto) -> int:
return x.meth()
func(C()) # Passes static type check
See PEP 544 for details. Protocol classes decorated with
@typing_extensions.runtime act as simple-minded runtime protocol that checks
only the presence of given attributes, ignoring their type signatures.
Protocol classes can be generic, they are defined as::
class GenProto(Protocol[T]):
def meth(self) -> T:
...
"""
__slots__ = ()
_is_protocol = True
def __new__(cls, *args, **kwds):
if cls is Protocol:
raise TypeError("Type Protocol cannot be instantiated; "
"it can only be used as a base class")
return super().__new__(cls)
@typing._tp_cache
def __class_getitem__(cls, params):
if not isinstance(params, tuple):
params = (params,)
if not params and cls is not typing.Tuple:
raise TypeError(
f"Parameter list to {cls.__qualname__}[...] cannot be empty")
msg = "Parameters to generic types must be types."
params = tuple(typing._type_check(p, msg) for p in params) # noqa
if cls is Protocol:
# Generic can only be subscripted with unique type variables.
if not all(isinstance(p, typing.TypeVar) for p in params):
i = 0
while isinstance(params[i], typing.TypeVar):
i += 1
raise TypeError(
"Parameters to Protocol[...] must all be type variables."
f" Parameter {i + 1} is {params[i]}")
if len(set(params)) != len(params):
raise TypeError(
"Parameters to Protocol[...] must all be unique")
else:
# Subscripting a regular Generic subclass.
_check_generic(cls, params)
return typing._GenericAlias(cls, params)
def __init_subclass__(cls, *args, **kwargs):
tvars = []
if '__orig_bases__' in cls.__dict__:
error = typing.Generic in cls.__orig_bases__
else:
error = typing.Generic in cls.__bases__
if error:
raise TypeError("Cannot inherit from plain Generic")
if '__orig_bases__' in cls.__dict__:
tvars = _collect_type_vars(cls.__orig_bases__)
# Look for Generic[T1, ..., Tn] or Protocol[T1, ..., Tn].
# If found, tvars must be a subset of it.
# If not found, tvars is it.
# Also check for and reject plain Generic,
# and reject multiple Generic[...] and/or Protocol[...].
gvars = None
for base in cls.__orig_bases__:
if (isinstance(base, typing._GenericAlias) and
base.__origin__ in (typing.Generic, Protocol)):
# for error messages
the_base = base.__origin__.__name__
if gvars is not None:
raise TypeError(
"Cannot inherit from Generic[...]"
" and/or Protocol[...] multiple types.")
gvars = base.__parameters__
if gvars is None:
gvars = tvars
else:
tvarset = set(tvars)
gvarset = set(gvars)
if not tvarset <= gvarset:
s_vars = ', '.join(str(t) for t in tvars if t not in gvarset)
s_args = ', '.join(str(g) for g in gvars)
raise TypeError(f"Some type variables ({s_vars}) are"
f" not listed in {the_base}[{s_args}]")
tvars = gvars
cls.__parameters__ = tuple(tvars)
# Determine if this is a protocol or a concrete subclass.
if not cls.__dict__.get('_is_protocol', None):
cls._is_protocol = any(b is Protocol for b in cls.__bases__)
# Set (or override) the protocol subclass hook.
def _proto_hook(other):
if not cls.__dict__.get('_is_protocol', None):
return NotImplemented
if not getattr(cls, '_is_runtime_protocol', False):
if sys._getframe(2).f_globals['__name__'] in ['abc', 'functools']:
return NotImplemented
raise TypeError("Instance and class checks can only be used with"
" @runtime protocols")
if not _is_callable_members_only(cls):
if sys._getframe(2).f_globals['__name__'] in ['abc', 'functools']:
return NotImplemented
raise TypeError("Protocols with non-method members"
" don't support issubclass()")
if not isinstance(other, type):
# Same error as for issubclass(1, int)
raise TypeError('issubclass() arg 1 must be a class')
for attr in _get_protocol_attrs(cls):
for base in other.__mro__:
if attr in base.__dict__:
if base.__dict__[attr] is None:
return NotImplemented
break
annotations = getattr(base, '__annotations__', {})
if (isinstance(annotations, typing.Mapping) and
attr in annotations and
isinstance(other, _ProtocolMeta) and
other._is_protocol):
break
else:
return NotImplemented
return True
if '__subclasshook__' not in cls.__dict__:
cls.__subclasshook__ = _proto_hook
# We have nothing more to do for non-protocols.
if not cls._is_protocol:
return
# Check consistency of bases.
for base in cls.__bases__:
if not (base in (object, typing.Generic) or
base.__module__ == 'collections.abc' and
base.__name__ in _PROTO_WHITELIST or
isinstance(base, _ProtocolMeta) and base._is_protocol):
raise TypeError('Protocols can only inherit from other'
f' protocols, got {repr(base)}')
cls.__init__ = _no_init
# 3.6
else:
from typing import _next_in_mro, _type_check # noqa
def _no_init(self, *args, **kwargs):
if type(self)._is_protocol:
raise TypeError('Protocols cannot be instantiated')
class _ProtocolMeta(GenericMeta):
"""Internal metaclass for Protocol.
This exists so Protocol classes can be generic without deriving
from Generic.
"""
def __new__(cls, name, bases, namespace,
tvars=None, args=None, origin=None, extra=None, orig_bases=None):
# This is just a version copied from GenericMeta.__new__ that
# includes "Protocol" special treatment. (Comments removed for brevity.)
assert extra is None # Protocols should not have extra
if tvars is not None:
assert origin is not None
assert all(isinstance(t, typing.TypeVar) for t in tvars), tvars
else:
tvars = _type_vars(bases)
gvars = None
for base in bases:
if base is typing.Generic:
raise TypeError("Cannot inherit from plain Generic")
if (isinstance(base, GenericMeta) and
base.__origin__ in (typing.Generic, Protocol)):
if gvars is not None:
raise TypeError(
"Cannot inherit from Generic[...] or"
" Protocol[...] multiple times.")
gvars = base.__parameters__
if gvars is None:
gvars = tvars
else:
tvarset = set(tvars)
gvarset = set(gvars)
if not tvarset <= gvarset:
s_vars = ", ".join(str(t) for t in tvars if t not in gvarset)
s_args = ", ".join(str(g) for g in gvars)
cls_name = "Generic" if any(b.__origin__ is typing.Generic
for b in bases) else "Protocol"
raise TypeError(f"Some type variables ({s_vars}) are"
f" not listed in {cls_name}[{s_args}]")
tvars = gvars
initial_bases = bases
if (extra is not None and type(extra) is abc.ABCMeta and
extra not in bases):
bases = (extra,) + bases
bases = tuple(_gorg(b) if isinstance(b, GenericMeta) else b
for b in bases)
if any(isinstance(b, GenericMeta) and b is not typing.Generic for b in bases):
bases = tuple(b for b in bases if b is not typing.Generic)
namespace.update({'__origin__': origin, '__extra__': extra})
self = super(GenericMeta, cls).__new__(cls, name, bases, namespace,
_root=True)
super(GenericMeta, self).__setattr__('_gorg',
self if not origin else
_gorg(origin))
self.__parameters__ = tvars
self.__args__ = tuple(... if a is typing._TypingEllipsis else
() if a is typing._TypingEmpty else
a for a in args) if args else None
self.__next_in_mro__ = _next_in_mro(self)
if orig_bases is None:
self.__orig_bases__ = initial_bases
elif origin is not None:
self._abc_registry = origin._abc_registry
self._abc_cache = origin._abc_cache
if hasattr(self, '_subs_tree'):
self.__tree_hash__ = (hash(self._subs_tree()) if origin else
super(GenericMeta, self).__hash__())
return self
def __init__(cls, *args, **kwargs):
super().__init__(*args, **kwargs)
if not cls.__dict__.get('_is_protocol', None):
cls._is_protocol = any(b is Protocol or
isinstance(b, _ProtocolMeta) and
b.__origin__ is Protocol
for b in cls.__bases__)
if cls._is_protocol:
for base in cls.__mro__[1:]:
if not (base in (object, typing.Generic) or
base.__module__ == 'collections.abc' and
base.__name__ in _PROTO_WHITELIST or
isinstance(base, typing.TypingMeta) and base._is_protocol or
isinstance(base, GenericMeta) and
base.__origin__ is typing.Generic):
raise TypeError(f'Protocols can only inherit from other'
f' protocols, got {repr(base)}')
cls.__init__ = _no_init
def _proto_hook(other):
if not cls.__dict__.get('_is_protocol', None):
return NotImplemented
if not isinstance(other, type):
# Same error as for issubclass(1, int)
raise TypeError('issubclass() arg 1 must be a class')
for attr in _get_protocol_attrs(cls):
for base in other.__mro__:
if attr in base.__dict__:
if base.__dict__[attr] is None:
return NotImplemented
break
annotations = getattr(base, '__annotations__', {})
if (isinstance(annotations, typing.Mapping) and
attr in annotations and
isinstance(other, _ProtocolMeta) and
other._is_protocol):
break
else:
return NotImplemented
return True
if '__subclasshook__' not in cls.__dict__:
cls.__subclasshook__ = _proto_hook
def __instancecheck__(self, instance):
# We need this method for situations where attributes are
# assigned in __init__.
if ((not getattr(self, '_is_protocol', False) or
_is_callable_members_only(self)) and
issubclass(instance.__class__, self)):
return True
if self._is_protocol:
if all(hasattr(instance, attr) and
(not callable(getattr(self, attr, None)) or
getattr(instance, attr) is not None)
for attr in _get_protocol_attrs(self)):
return True
return super(GenericMeta, self).__instancecheck__(instance)
def __subclasscheck__(self, cls):
if self.__origin__ is not None:
if sys._getframe(1).f_globals['__name__'] not in ['abc', 'functools']:
raise TypeError("Parameterized generics cannot be used with class "
"or instance checks")
return False
if (self.__dict__.get('_is_protocol', None) and
not self.__dict__.get('_is_runtime_protocol', None)):
if sys._getframe(1).f_globals['__name__'] in ['abc',
'functools',
'typing']:
return False
raise TypeError("Instance and class checks can only be used with"
" @runtime protocols")
if (self.__dict__.get('_is_runtime_protocol', None) and
not _is_callable_members_only(self)):
if sys._getframe(1).f_globals['__name__'] in ['abc',
'functools',
'typing']:
return super(GenericMeta, self).__subclasscheck__(cls)
raise TypeError("Protocols with non-method members"
" don't support issubclass()")
return super(GenericMeta, self).__subclasscheck__(cls)
@typing._tp_cache
def __getitem__(self, params):
# We also need to copy this from GenericMeta.__getitem__ to get
# special treatment of "Protocol". (Comments removed for brevity.)
if not isinstance(params, tuple):
params = (params,)
if not params and _gorg(self) is not typing.Tuple:
raise TypeError(
f"Parameter list to {self.__qualname__}[...] cannot be empty")
msg = "Parameters to generic types must be types."
params = tuple(_type_check(p, msg) for p in params)
if self in (typing.Generic, Protocol):
if not all(isinstance(p, typing.TypeVar) for p in params):
raise TypeError(
f"Parameters to {repr(self)}[...] must all be type variables")
if len(set(params)) != len(params):
raise TypeError(
f"Parameters to {repr(self)}[...] must all be unique")
tvars = params
args = params
elif self in (typing.Tuple, typing.Callable):
tvars = _type_vars(params)
args = params
elif self.__origin__ in (typing.Generic, Protocol):
raise TypeError(f"Cannot subscript already-subscripted {repr(self)}")
else:
_check_generic(self, params)
tvars = _type_vars(params)
args = params
prepend = (self,) if self.__origin__ is None else ()
return self.__class__(self.__name__,
prepend + self.__bases__,
_no_slots_copy(self.__dict__),
tvars=tvars,
args=args,
origin=self,
extra=self.__extra__,
orig_bases=self.__orig_bases__)
class Protocol(metaclass=_ProtocolMeta):
"""Base class for protocol classes. Protocol classes are defined as::
class Proto(Protocol):
def meth(self) -> int:
...
Such classes are primarily used with static type checkers that recognize
structural subtyping (static duck-typing), for example::
class C:
def meth(self) -> int:
return 0
def func(x: Proto) -> int:
return x.meth()
func(C()) # Passes static type check
See PEP 544 for details. Protocol classes decorated with
@typing_extensions.runtime act as simple-minded runtime protocol that checks
only the presence of given attributes, ignoring their type signatures.
Protocol classes can be generic, they are defined as::
class GenProto(Protocol[T]):
def meth(self) -> T:
...
"""
__slots__ = ()
_is_protocol = True
def __new__(cls, *args, **kwds):
if _gorg(cls) is Protocol:
raise TypeError("Type Protocol cannot be instantiated; "
"it can be used only as a base class")
return typing._generic_new(cls.__next_in_mro__, cls, *args, **kwds)
# 3.8+
if hasattr(typing, 'runtime_checkable'):
runtime_checkable = typing.runtime_checkable
# 3.6-3.7
else:
def runtime_checkable(cls):
"""Mark a protocol class as a runtime protocol, so that it
can be used with isinstance() and issubclass(). Raise TypeError
if applied to a non-protocol class.
This allows a simple-minded structural check very similar to the
one-offs in collections.abc such as Hashable.
"""
if not isinstance(cls, _ProtocolMeta) or not cls._is_protocol:
raise TypeError('@runtime_checkable can be only applied to protocol classes,'
f' got {cls!r}')
cls._is_runtime_protocol = True
return cls
# Exists for backwards compatibility.
runtime = runtime_checkable
# 3.8+
if hasattr(typing, 'SupportsIndex'):
SupportsIndex = typing.SupportsIndex
# 3.6-3.7
else:
@runtime_checkable
class SupportsIndex(Protocol):
__slots__ = ()
@abc.abstractmethod
def __index__(self) -> int:
pass
if sys.version_info >= (3, 9, 2):
# The standard library TypedDict in Python 3.8 does not store runtime information
# about which (if any) keys are optional. See https://bugs.python.org/issue38834
# The standard library TypedDict in Python 3.9.0/1 does not honour the "total"
# keyword with old-style TypedDict(). See https://bugs.python.org/issue42059
TypedDict = typing.TypedDict
else:
def _check_fails(cls, other):
try:
if sys._getframe(1).f_globals['__name__'] not in ['abc',
'functools',
'typing']:
# Typed dicts are only for static structural subtyping.
raise TypeError('TypedDict does not support instance and class checks')
except (AttributeError, ValueError):
pass
return False
def _dict_new(*args, **kwargs):
if not args:
raise TypeError('TypedDict.__new__(): not enough arguments')
_, args = args[0], args[1:] # allow the "cls" keyword be passed
return dict(*args, **kwargs)
_dict_new.__text_signature__ = '($cls, _typename, _fields=None, /, **kwargs)'
def _typeddict_new(*args, total=True, **kwargs):
if not args:
raise TypeError('TypedDict.__new__(): not enough arguments')
_, args = args[0], args[1:] # allow the "cls" keyword be passed
if args:
typename, args = args[0], args[1:] # allow the "_typename" keyword be passed
elif '_typename' in kwargs:
typename = kwargs.pop('_typename')
import warnings
warnings.warn("Passing '_typename' as keyword argument is deprecated",
DeprecationWarning, stacklevel=2)
else:
raise TypeError("TypedDict.__new__() missing 1 required positional "
"argument: '_typename'")
if args:
try:
fields, = args # allow the "_fields" keyword be passed
except ValueError:
raise TypeError('TypedDict.__new__() takes from 2 to 3 '
f'positional arguments but {len(args) + 2} '
'were given')
elif '_fields' in kwargs and len(kwargs) == 1:
fields = kwargs.pop('_fields')
import warnings
warnings.warn("Passing '_fields' as keyword argument is deprecated",
DeprecationWarning, stacklevel=2)
else:
fields = None
if fields is None:
fields = kwargs
elif kwargs:
raise TypeError("TypedDict takes either a dict or keyword arguments,"
" but not both")
ns = {'__annotations__': dict(fields)}
try:
# Setting correct module is necessary to make typed dict classes pickleable.
ns['__module__'] = sys._getframe(1).f_globals.get('__name__', '__main__')
except (AttributeError, ValueError):
pass
return _TypedDictMeta(typename, (), ns, total=total)
_typeddict_new.__text_signature__ = ('($cls, _typename, _fields=None,'
' /, *, total=True, **kwargs)')
class _TypedDictMeta(type):
def __init__(cls, name, bases, ns, total=True):
super().__init__(name, bases, ns)
def __new__(cls, name, bases, ns, total=True):
# Create new typed dict class object.
# This method is called directly when TypedDict is subclassed,
# or via _typeddict_new when TypedDict is instantiated. This way
# TypedDict supports all three syntaxes described in its docstring.
# Subclasses and instances of TypedDict return actual dictionaries
# via _dict_new.
ns['__new__'] = _typeddict_new if name == 'TypedDict' else _dict_new
tp_dict = super().__new__(cls, name, (dict,), ns)
annotations = {}
own_annotations = ns.get('__annotations__', {})
own_annotation_keys = set(own_annotations.keys())
msg = "TypedDict('Name', {f0: t0, f1: t1, ...}); each t must be a type"
own_annotations = {
n: typing._type_check(tp, msg) for n, tp in own_annotations.items()
}
required_keys = set()
optional_keys = set()
for base in bases:
annotations.update(base.__dict__.get('__annotations__', {}))
required_keys.update(base.__dict__.get('__required_keys__', ()))
optional_keys.update(base.__dict__.get('__optional_keys__', ()))
annotations.update(own_annotations)
if total:
required_keys.update(own_annotation_keys)
else:
optional_keys.update(own_annotation_keys)
tp_dict.__annotations__ = annotations
tp_dict.__required_keys__ = frozenset(required_keys)
tp_dict.__optional_keys__ = frozenset(optional_keys)
if not hasattr(tp_dict, '__total__'):
tp_dict.__total__ = total
return tp_dict
__instancecheck__ = __subclasscheck__ = _check_fails
TypedDict = _TypedDictMeta('TypedDict', (dict,), {})
TypedDict.__module__ = __name__
TypedDict.__doc__ = \
"""A simple typed name space. At runtime it is equivalent to a plain dict.
TypedDict creates a dictionary type that expects all of its
instances to have a certain set of keys, with each key
associated with a value of a consistent type. This expectation
is not checked at runtime but is only enforced by type checkers.
Usage::
class Point2D(TypedDict):
x: int
y: int
label: str
a: Point2D = {'x': 1, 'y': 2, 'label': 'good'} # OK
b: Point2D = {'z': 3, 'label': 'bad'} # Fails type check
assert Point2D(x=1, y=2, label='first') == dict(x=1, y=2, label='first')
The type info can be accessed via the Point2D.__annotations__ dict, and
the Point2D.__required_keys__ and Point2D.__optional_keys__ frozensets.
TypedDict supports two additional equivalent forms::
Point2D = TypedDict('Point2D', x=int, y=int, label=str)
Point2D = TypedDict('Point2D', {'x': int, 'y': int, 'label': str})
The class syntax is only supported in Python 3.6+, while two other
syntax forms work for Python 2.7 and 3.2+
"""
# Python 3.9+ has PEP 593 (Annotated and modified get_type_hints)
if hasattr(typing, 'Annotated'):
Annotated = typing.Annotated
get_type_hints = typing.get_type_hints
# Not exported and not a public API, but needed for get_origin() and get_args()
# to work.
_AnnotatedAlias = typing._AnnotatedAlias
# 3.7-3.8
elif PEP_560:
class _AnnotatedAlias(typing._GenericAlias, _root=True):
"""Runtime representation of an annotated type.
At its core 'Annotated[t, dec1, dec2, ...]' is an alias for the type 't'
with extra annotations. The alias behaves like a normal typing alias,
instantiating is the same as instantiating the underlying type, binding
it to types is also the same.
"""
def __init__(self, origin, metadata):
if isinstance(origin, _AnnotatedAlias):
metadata = origin.__metadata__ + metadata
origin = origin.__origin__
super().__init__(origin, origin)
self.__metadata__ = metadata
def copy_with(self, params):
assert len(params) == 1
new_type = params[0]
return _AnnotatedAlias(new_type, self.__metadata__)
def __repr__(self):
return (f"typing_extensions.Annotated[{typing._type_repr(self.__origin__)}, "
f"{', '.join(repr(a) for a in self.__metadata__)}]")
def __reduce__(self):
return operator.getitem, (
Annotated, (self.__origin__,) + self.__metadata__
)
def __eq__(self, other):
if not isinstance(other, _AnnotatedAlias):
return NotImplemented
if self.__origin__ != other.__origin__:
return False
return self.__metadata__ == other.__metadata__
def __hash__(self):
return hash((self.__origin__, self.__metadata__))
class Annotated:
"""Add context specific metadata to a type.
Example: Annotated[int, runtime_check.Unsigned] indicates to the
hypothetical runtime_check module that this type is an unsigned int.
Every other consumer of this type can ignore this metadata and treat
this type as int.
The first argument to Annotated must be a valid type (and will be in
the __origin__ field), the remaining arguments are kept as a tuple in
the __extra__ field.
Details:
- It's an error to call `Annotated` with less than two arguments.
- Nested Annotated are flattened::
Annotated[Annotated[T, Ann1, Ann2], Ann3] == Annotated[T, Ann1, Ann2, Ann3]
- Instantiating an annotated type is equivalent to instantiating the
underlying type::
Annotated[C, Ann1](5) == C(5)
- Annotated can be used as a generic type alias::
Optimized = Annotated[T, runtime.Optimize()]
Optimized[int] == Annotated[int, runtime.Optimize()]
OptimizedList = Annotated[List[T], runtime.Optimize()]
OptimizedList[int] == Annotated[List[int], runtime.Optimize()]
"""
__slots__ = ()
def __new__(cls, *args, **kwargs):
raise TypeError("Type Annotated cannot be instantiated.")
@typing._tp_cache
def __class_getitem__(cls, params):
if not isinstance(params, tuple) or len(params) < 2:
raise TypeError("Annotated[...] should be used "
"with at least two arguments (a type and an "
"annotation).")
msg = "Annotated[t, ...]: t must be a type."
origin = typing._type_check(params[0], msg)
metadata = tuple(params[1:])
return _AnnotatedAlias(origin, metadata)
def __init_subclass__(cls, *args, **kwargs):
raise TypeError(
f"Cannot subclass {cls.__module__}.Annotated"
)
def _strip_annotations(t):
"""Strips the annotations from a given type.
"""
if isinstance(t, _AnnotatedAlias):
return _strip_annotations(t.__origin__)
if isinstance(t, typing._GenericAlias):
stripped_args = tuple(_strip_annotations(a) for a in t.__args__)
if stripped_args == t.__args__:
return t
res = t.copy_with(stripped_args)
res._special = t._special
return res
return t
def get_type_hints(obj, globalns=None, localns=None, include_extras=False):
"""Return type hints for an object.
This is often the same as obj.__annotations__, but it handles
forward references encoded as string literals, adds Optional[t] if a
default value equal to None is set and recursively replaces all
'Annotated[T, ...]' with 'T' (unless 'include_extras=True').
The argument may be a module, class, method, or function. The annotations
are returned as a dictionary. For classes, annotations include also
inherited members.
TypeError is raised if the argument is not of a type that can contain
annotations, and an empty dictionary is returned if no annotations are
present.
BEWARE -- the behavior of globalns and localns is counterintuitive
(unless you are familiar with how eval() and exec() work). The
search order is locals first, then globals.
- If no dict arguments are passed, an attempt is made to use the
globals from obj (or the respective module's globals for classes),
and these are also used as the locals. If the object does not appear
to have globals, an empty dictionary is used.
- If one dict argument is passed, it is used for both globals and
locals.
- If two dict arguments are passed, they specify globals and
locals, respectively.
"""
hint = typing.get_type_hints(obj, globalns=globalns, localns=localns)
if include_extras:
return hint
return {k: _strip_annotations(t) for k, t in hint.items()}
# 3.6
else:
def _is_dunder(name):
"""Returns True if name is a __dunder_variable_name__."""
return len(name) > 4 and name.startswith('__') and name.endswith('__')
# Prior to Python 3.7 types did not have `copy_with`. A lot of the equality
# checks, argument expansion etc. are done on the _subs_tre. As a result we
# can't provide a get_type_hints function that strips out annotations.
class AnnotatedMeta(typing.GenericMeta):
"""Metaclass for Annotated"""
def __new__(cls, name, bases, namespace, **kwargs):
if any(b is not object for b in bases):
raise TypeError("Cannot subclass " + str(Annotated))
return super().__new__(cls, name, bases, namespace, **kwargs)
@property
def __metadata__(self):
return self._subs_tree()[2]
def _tree_repr(self, tree):
cls, origin, metadata = tree
if not isinstance(origin, tuple):
tp_repr = typing._type_repr(origin)
else:
tp_repr = origin[0]._tree_repr(origin)
metadata_reprs = ", ".join(repr(arg) for arg in metadata)
return f'{cls}[{tp_repr}, {metadata_reprs}]'
def _subs_tree(self, tvars=None, args=None): # noqa
if self is Annotated:
return Annotated
res = super()._subs_tree(tvars=tvars, args=args)
# Flatten nested Annotated
if isinstance(res[1], tuple) and res[1][0] is Annotated:
sub_tp = res[1][1]
sub_annot = res[1][2]
return (Annotated, sub_tp, sub_annot + res[2])
return res
def _get_cons(self):
"""Return the class used to create instance of this type."""
if self.__origin__ is None:
raise TypeError("Cannot get the underlying type of a "
"non-specialized Annotated type.")
tree = self._subs_tree()
while isinstance(tree, tuple) and tree[0] is Annotated:
tree = tree[1]
if isinstance(tree, tuple):
return tree[0]
else:
return tree
@typing._tp_cache
def __getitem__(self, params):
if not isinstance(params, tuple):
params = (params,)
if self.__origin__ is not None: # specializing an instantiated type
return super().__getitem__(params)
elif not isinstance(params, tuple) or len(params) < 2:
raise TypeError("Annotated[...] should be instantiated "
"with at least two arguments (a type and an "
"annotation).")
else:
msg = "Annotated[t, ...]: t must be a type."
tp = typing._type_check(params[0], msg)
metadata = tuple(params[1:])
return self.__class__(
self.__name__,
self.__bases__,
_no_slots_copy(self.__dict__),
tvars=_type_vars((tp,)),
# Metadata is a tuple so it won't be touched by _replace_args et al.
args=(tp, metadata),
origin=self,
)
def __call__(self, *args, **kwargs):
cons = self._get_cons()
result = cons(*args, **kwargs)
try:
result.__orig_class__ = self
except AttributeError:
pass
return result
def __getattr__(self, attr):
# For simplicity we just don't relay all dunder names
if self.__origin__ is not None and not _is_dunder(attr):
return getattr(self._get_cons(), attr)
raise AttributeError(attr)
def __setattr__(self, attr, value):
if _is_dunder(attr) or attr.startswith('_abc_'):
super().__setattr__(attr, value)
elif self.__origin__ is None:
raise AttributeError(attr)
else:
setattr(self._get_cons(), attr, value)
def __instancecheck__(self, obj):
raise TypeError("Annotated cannot be used with isinstance().")
def __subclasscheck__(self, cls):
raise TypeError("Annotated cannot be used with issubclass().")
class Annotated(metaclass=AnnotatedMeta):
"""Add context specific metadata to a type.
Example: Annotated[int, runtime_check.Unsigned] indicates to the
hypothetical runtime_check module that this type is an unsigned int.
Every other consumer of this type can ignore this metadata and treat
this type as int.
The first argument to Annotated must be a valid type, the remaining
arguments are kept as a tuple in the __metadata__ field.
Details:
- It's an error to call `Annotated` with less than two arguments.
- Nested Annotated are flattened::
Annotated[Annotated[T, Ann1, Ann2], Ann3] == Annotated[T, Ann1, Ann2, Ann3]
- Instantiating an annotated type is equivalent to instantiating the
underlying type::
Annotated[C, Ann1](5) == C(5)
- Annotated can be used as a generic type alias::
Optimized = Annotated[T, runtime.Optimize()]
Optimized[int] == Annotated[int, runtime.Optimize()]
OptimizedList = Annotated[List[T], runtime.Optimize()]
OptimizedList[int] == Annotated[List[int], runtime.Optimize()]
"""
# Python 3.8 has get_origin() and get_args() but those implementations aren't
# Annotated-aware, so we can't use those. Python 3.9's versions don't support
# ParamSpecArgs and ParamSpecKwargs, so only Python 3.10's versions will do.
if sys.version_info[:2] >= (3, 10):
get_origin = typing.get_origin
get_args = typing.get_args
# 3.7-3.9
elif PEP_560:
try:
# 3.9+
from typing import _BaseGenericAlias
except ImportError:
_BaseGenericAlias = typing._GenericAlias
try:
# 3.9+
from typing import GenericAlias
except ImportError:
GenericAlias = typing._GenericAlias
def get_origin(tp):
"""Get the unsubscripted version of a type.
This supports generic types, Callable, Tuple, Union, Literal, Final, ClassVar
and Annotated. Return None for unsupported types. Examples::
get_origin(Literal[42]) is Literal
get_origin(int) is None
get_origin(ClassVar[int]) is ClassVar
get_origin(Generic) is Generic
get_origin(Generic[T]) is Generic
get_origin(Union[T, int]) is Union
get_origin(List[Tuple[T, T]][int]) == list
get_origin(P.args) is P
"""
if isinstance(tp, _AnnotatedAlias):
return Annotated
if isinstance(tp, (typing._GenericAlias, GenericAlias, _BaseGenericAlias,
ParamSpecArgs, ParamSpecKwargs)):
return tp.__origin__
if tp is typing.Generic:
return typing.Generic
return None
def get_args(tp):
"""Get type arguments with all substitutions performed.
For unions, basic simplifications used by Union constructor are performed.
Examples::
get_args(Dict[str, int]) == (str, int)
get_args(int) == ()
get_args(Union[int, Union[T, int], str][int]) == (int, str)
get_args(Union[int, Tuple[T, int]][str]) == (int, Tuple[str, int])
get_args(Callable[[], T][int]) == ([], int)
"""
if isinstance(tp, _AnnotatedAlias):
return (tp.__origin__,) + tp.__metadata__
if isinstance(tp, (typing._GenericAlias, GenericAlias)):
if getattr(tp, "_special", False):
return ()
res = tp.__args__
if get_origin(tp) is collections.abc.Callable and res[0] is not Ellipsis:
res = (list(res[:-1]), res[-1])
return res
return ()
# 3.10+
if hasattr(typing, 'TypeAlias'):
TypeAlias = typing.TypeAlias
# 3.9
elif sys.version_info[:2] >= (3, 9):
class _TypeAliasForm(typing._SpecialForm, _root=True):
def __repr__(self):
return 'typing_extensions.' + self._name
@_TypeAliasForm
def TypeAlias(self, parameters):
"""Special marker indicating that an assignment should
be recognized as a proper type alias definition by type
checkers.
For example::
Predicate: TypeAlias = Callable[..., bool]
It's invalid when used anywhere except as in the example above.
"""
raise TypeError(f"{self} is not subscriptable")
# 3.7-3.8
elif sys.version_info[:2] >= (3, 7):
class _TypeAliasForm(typing._SpecialForm, _root=True):
def __repr__(self):
return 'typing_extensions.' + self._name
TypeAlias = _TypeAliasForm('TypeAlias',
doc="""Special marker indicating that an assignment should
be recognized as a proper type alias definition by type
checkers.
For example::
Predicate: TypeAlias = Callable[..., bool]
It's invalid when used anywhere except as in the example
above.""")
# 3.6
else:
class _TypeAliasMeta(typing.TypingMeta):
"""Metaclass for TypeAlias"""
def __repr__(self):
return 'typing_extensions.TypeAlias'
class _TypeAliasBase(typing._FinalTypingBase, metaclass=_TypeAliasMeta, _root=True):
"""Special marker indicating that an assignment should
be recognized as a proper type alias definition by type
checkers.
For example::
Predicate: TypeAlias = Callable[..., bool]
It's invalid when used anywhere except as in the example above.
"""
__slots__ = ()
def __instancecheck__(self, obj):
raise TypeError("TypeAlias cannot be used with isinstance().")
def __subclasscheck__(self, cls):
raise TypeError("TypeAlias cannot be used with issubclass().")
def __repr__(self):
return 'typing_extensions.TypeAlias'
TypeAlias = _TypeAliasBase(_root=True)
# Python 3.10+ has PEP 612
if hasattr(typing, 'ParamSpecArgs'):
ParamSpecArgs = typing.ParamSpecArgs
ParamSpecKwargs = typing.ParamSpecKwargs
# 3.6-3.9
else:
class _Immutable:
"""Mixin to indicate that object should not be copied."""
__slots__ = ()
def __copy__(self):
return self
def __deepcopy__(self, memo):
return self
class ParamSpecArgs(_Immutable):
"""The args for a ParamSpec object.
Given a ParamSpec object P, P.args is an instance of ParamSpecArgs.
ParamSpecArgs objects have a reference back to their ParamSpec:
P.args.__origin__ is P
This type is meant for runtime introspection and has no special meaning to
static type checkers.
"""
def __init__(self, origin):
self.__origin__ = origin
def __repr__(self):
return f"{self.__origin__.__name__}.args"
class ParamSpecKwargs(_Immutable):
"""The kwargs for a ParamSpec object.
Given a ParamSpec object P, P.kwargs is an instance of ParamSpecKwargs.
ParamSpecKwargs objects have a reference back to their ParamSpec:
P.kwargs.__origin__ is P
This type is meant for runtime introspection and has no special meaning to
static type checkers.
"""
def __init__(self, origin):
self.__origin__ = origin
def __repr__(self):
return f"{self.__origin__.__name__}.kwargs"
# 3.10+
if hasattr(typing, 'ParamSpec'):
ParamSpec = typing.ParamSpec
# 3.6-3.9
else:
# Inherits from list as a workaround for Callable checks in Python < 3.9.2.
class ParamSpec(list):
"""Parameter specification variable.
Usage::
P = ParamSpec('P')
Parameter specification variables exist primarily for the benefit of static
type checkers. They are used to forward the parameter types of one
callable to another callable, a pattern commonly found in higher order
functions and decorators. They are only valid when used in ``Concatenate``,
or s the first argument to ``Callable``. In Python 3.10 and higher,
they are also supported in user-defined Generics at runtime.
See class Generic for more information on generic types. An
example for annotating a decorator::
T = TypeVar('T')
P = ParamSpec('P')
def add_logging(f: Callable[P, T]) -> Callable[P, T]:
'''A type-safe decorator to add logging to a function.'''
def inner(*args: P.args, **kwargs: P.kwargs) -> T:
logging.info(f'{f.__name__} was called')
return f(*args, **kwargs)
return inner
@add_logging
def add_two(x: float, y: float) -> float:
'''Add two numbers together.'''
return x + y
Parameter specification variables defined with covariant=True or
contravariant=True can be used to declare covariant or contravariant
generic types. These keyword arguments are valid, but their actual semantics
are yet to be decided. See PEP 612 for details.
Parameter specification variables can be introspected. e.g.:
P.__name__ == 'T'
P.__bound__ == None
P.__covariant__ == False
P.__contravariant__ == False
Note that only parameter specification variables defined in global scope can
be pickled.
"""
# Trick Generic __parameters__.
__class__ = typing.TypeVar
@property
def args(self):
return ParamSpecArgs(self)
@property
def kwargs(self):
return ParamSpecKwargs(self)
def __init__(self, name, *, bound=None, covariant=False, contravariant=False):
super().__init__([self])
self.__name__ = name
self.__covariant__ = bool(covariant)
self.__contravariant__ = bool(contravariant)
if bound:
self.__bound__ = typing._type_check(bound, 'Bound must be a type.')
else:
self.__bound__ = None
# for pickling:
try:
def_mod = sys._getframe(1).f_globals.get('__name__', '__main__')
except (AttributeError, ValueError):
def_mod = None
if def_mod != 'typing_extensions':
self.__module__ = def_mod
def __repr__(self):
if self.__covariant__:
prefix = '+'
elif self.__contravariant__:
prefix = '-'
else:
prefix = '~'
return prefix + self.__name__
def __hash__(self):
return object.__hash__(self)
def __eq__(self, other):
return self is other
def __reduce__(self):
return self.__name__
# Hack to get typing._type_check to pass.
def __call__(self, *args, **kwargs):
pass
if not PEP_560:
# Only needed in 3.6.
def _get_type_vars(self, tvars):
if self not in tvars:
tvars.append(self)
# 3.6-3.9
if not hasattr(typing, 'Concatenate'):
# Inherits from list as a workaround for Callable checks in Python < 3.9.2.
class _ConcatenateGenericAlias(list):
# Trick Generic into looking into this for __parameters__.
if PEP_560:
__class__ = typing._GenericAlias
else:
__class__ = typing._TypingBase
# Flag in 3.8.
_special = False
# Attribute in 3.6 and earlier.
_gorg = typing.Generic
def __init__(self, origin, args):
super().__init__(args)
self.__origin__ = origin
self.__args__ = args
def __repr__(self):
_type_repr = typing._type_repr
return (f'{_type_repr(self.__origin__)}'
f'[{", ".join(_type_repr(arg) for arg in self.__args__)}]')
def __hash__(self):
return hash((self.__origin__, self.__args__))
# Hack to get typing._type_check to pass in Generic.
def __call__(self, *args, **kwargs):
pass
@property
def __parameters__(self):
return tuple(
tp for tp in self.__args__ if isinstance(tp, (typing.TypeVar, ParamSpec))
)
if not PEP_560:
# Only required in 3.6.
def _get_type_vars(self, tvars):
if self.__origin__ and self.__parameters__:
typing._get_type_vars(self.__parameters__, tvars)
# 3.6-3.9
@typing._tp_cache
def _concatenate_getitem(self, parameters):
if parameters == ():
raise TypeError("Cannot take a Concatenate of no types.")
if not isinstance(parameters, tuple):
parameters = (parameters,)
if not isinstance(parameters[-1], ParamSpec):
raise TypeError("The last parameter to Concatenate should be a "
"ParamSpec variable.")
msg = "Concatenate[arg, ...]: each arg must be a type."
parameters = tuple(typing._type_check(p, msg) for p in parameters)
return _ConcatenateGenericAlias(self, parameters)
# 3.10+
if hasattr(typing, 'Concatenate'):
Concatenate = typing.Concatenate
_ConcatenateGenericAlias = typing._ConcatenateGenericAlias # noqa
# 3.9
elif sys.version_info[:2] >= (3, 9):
@_TypeAliasForm
def Concatenate(self, parameters):
"""Used in conjunction with ``ParamSpec`` and ``Callable`` to represent a
higher order function which adds, removes or transforms parameters of a
callable.
For example::
Callable[Concatenate[int, P], int]
See PEP 612 for detailed information.
"""
return _concatenate_getitem(self, parameters)
# 3.7-8
elif sys.version_info[:2] >= (3, 7):
class _ConcatenateForm(typing._SpecialForm, _root=True):
def __repr__(self):
return 'typing_extensions.' + self._name
def __getitem__(self, parameters):
return _concatenate_getitem(self, parameters)
Concatenate = _ConcatenateForm(
'Concatenate',
doc="""Used in conjunction with ``ParamSpec`` and ``Callable`` to represent a
higher order function which adds, removes or transforms parameters of a
callable.
For example::
Callable[Concatenate[int, P], int]
See PEP 612 for detailed information.
""")
# 3.6
else:
class _ConcatenateAliasMeta(typing.TypingMeta):
"""Metaclass for Concatenate."""
def __repr__(self):
return 'typing_extensions.Concatenate'
class _ConcatenateAliasBase(typing._FinalTypingBase,
metaclass=_ConcatenateAliasMeta,
_root=True):
"""Used in conjunction with ``ParamSpec`` and ``Callable`` to represent a
higher order function which adds, removes or transforms parameters of a
callable.
For example::
Callable[Concatenate[int, P], int]
See PEP 612 for detailed information.
"""
__slots__ = ()
def __instancecheck__(self, obj):
raise TypeError("Concatenate cannot be used with isinstance().")
def __subclasscheck__(self, cls):
raise TypeError("Concatenate cannot be used with issubclass().")
def __repr__(self):
return 'typing_extensions.Concatenate'
def __getitem__(self, parameters):
return _concatenate_getitem(self, parameters)
Concatenate = _ConcatenateAliasBase(_root=True)
# 3.10+
if hasattr(typing, 'TypeGuard'):
TypeGuard = typing.TypeGuard
# 3.9
elif sys.version_info[:2] >= (3, 9):
class _TypeGuardForm(typing._SpecialForm, _root=True):
def __repr__(self):
return 'typing_extensions.' + self._name
@_TypeGuardForm
def TypeGuard(self, parameters):
"""Special typing form used to annotate the return type of a user-defined
type guard function. ``TypeGuard`` only accepts a single type argument.
At runtime, functions marked this way should return a boolean.
``TypeGuard`` aims to benefit *type narrowing* -- a technique used by static
type checkers to determine a more precise type of an expression within a
program's code flow. Usually type narrowing is done by analyzing
conditional code flow and applying the narrowing to a block of code. The
conditional expression here is sometimes referred to as a "type guard".
Sometimes it would be convenient to use a user-defined boolean function
as a type guard. Such a function should use ``TypeGuard[...]`` as its
return type to alert static type checkers to this intention.
Using ``-> TypeGuard`` tells the static type checker that for a given
function:
1. The return value is a boolean.
2. If the return value is ``True``, the type of its argument
is the type inside ``TypeGuard``.
For example::
def is_str(val: Union[str, float]):
# "isinstance" type guard
if isinstance(val, str):
# Type of ``val`` is narrowed to ``str``
...
else:
# Else, type of ``val`` is narrowed to ``float``.
...
Strict type narrowing is not enforced -- ``TypeB`` need not be a narrower
form of ``TypeA`` (it can even be a wider form) and this may lead to
type-unsafe results. The main reason is to allow for things like
narrowing ``List[object]`` to ``List[str]`` even though the latter is not
a subtype of the former, since ``List`` is invariant. The responsibility of
writing type-safe type guards is left to the user.
``TypeGuard`` also works with type variables. For more information, see
PEP 647 (User-Defined Type Guards).
"""
item = typing._type_check(parameters, f'{self} accepts only single type.')
return typing._GenericAlias(self, (item,))
# 3.7-3.8
elif sys.version_info[:2] >= (3, 7):
class _TypeGuardForm(typing._SpecialForm, _root=True):
def __repr__(self):
return 'typing_extensions.' + self._name
def __getitem__(self, parameters):
item = typing._type_check(parameters,
f'{self._name} accepts only a single type')
return typing._GenericAlias(self, (item,))
TypeGuard = _TypeGuardForm(
'TypeGuard',
doc="""Special typing form used to annotate the return type of a user-defined
type guard function. ``TypeGuard`` only accepts a single type argument.
At runtime, functions marked this way should return a boolean.
``TypeGuard`` aims to benefit *type narrowing* -- a technique used by static
type checkers to determine a more precise type of an expression within a
program's code flow. Usually type narrowing is done by analyzing
conditional code flow and applying the narrowing to a block of code. The
conditional expression here is sometimes referred to as a "type guard".
Sometimes it would be convenient to use a user-defined boolean function
as a type guard. Such a function should use ``TypeGuard[...]`` as its
return type to alert static type checkers to this intention.
Using ``-> TypeGuard`` tells the static type checker that for a given
function:
1. The return value is a boolean.
2. If the return value is ``True``, the type of its argument
is the type inside ``TypeGuard``.
For example::
def is_str(val: Union[str, float]):
# "isinstance" type guard
if isinstance(val, str):
# Type of ``val`` is narrowed to ``str``
...
else:
# Else, type of ``val`` is narrowed to ``float``.
...
Strict type narrowing is not enforced -- ``TypeB`` need not be a narrower
form of ``TypeA`` (it can even be a wider form) and this may lead to
type-unsafe results. The main reason is to allow for things like
narrowing ``List[object]`` to ``List[str]`` even though the latter is not
a subtype of the former, since ``List`` is invariant. The responsibility of
writing type-safe type guards is left to the user.
``TypeGuard`` also works with type variables. For more information, see
PEP 647 (User-Defined Type Guards).
""")
# 3.6
else:
class _TypeGuard(typing._FinalTypingBase, _root=True):
"""Special typing form used to annotate the return type of a user-defined
type guard function. ``TypeGuard`` only accepts a single type argument.
At runtime, functions marked this way should return a boolean.
``TypeGuard`` aims to benefit *type narrowing* -- a technique used by static
type checkers to determine a more precise type of an expression within a
program's code flow. Usually type narrowing is done by analyzing
conditional code flow and applying the narrowing to a block of code. The
conditional expression here is sometimes referred to as a "type guard".
Sometimes it would be convenient to use a user-defined boolean function
as a type guard. Such a function should use ``TypeGuard[...]`` as its
return type to alert static type checkers to this intention.
Using ``-> TypeGuard`` tells the static type checker that for a given
function:
1. The return value is a boolean.
2. If the return value is ``True``, the type of its argument
is the type inside ``TypeGuard``.
For example::
def is_str(val: Union[str, float]):
# "isinstance" type guard
if isinstance(val, str):
# Type of ``val`` is narrowed to ``str``
...
else:
# Else, type of ``val`` is narrowed to ``float``.
...
Strict type narrowing is not enforced -- ``TypeB`` need not be a narrower
form of ``TypeA`` (it can even be a wider form) and this may lead to
type-unsafe results. The main reason is to allow for things like
narrowing ``List[object]`` to ``List[str]`` even though the latter is not
a subtype of the former, since ``List`` is invariant. The responsibility of
writing type-safe type guards is left to the user.
``TypeGuard`` also works with type variables. For more information, see
PEP 647 (User-Defined Type Guards).
"""
__slots__ = ('__type__',)
def __init__(self, tp=None, **kwds):
self.__type__ = tp
def __getitem__(self, item):
cls = type(self)
if self.__type__ is None:
return cls(typing._type_check(item,
f'{cls.__name__[1:]} accepts only a single type.'),
_root=True)
raise TypeError(f'{cls.__name__[1:]} cannot be further subscripted')
def _eval_type(self, globalns, localns):
new_tp = typing._eval_type(self.__type__, globalns, localns)
if new_tp == self.__type__:
return self
return type(self)(new_tp, _root=True)
def __repr__(self):
r = super().__repr__()
if self.__type__ is not None:
r += f'[{typing._type_repr(self.__type__)}]'
return r
def __hash__(self):
return hash((type(self).__name__, self.__type__))
def __eq__(self, other):
if not isinstance(other, _TypeGuard):
return NotImplemented
if self.__type__ is not None:
return self.__type__ == other.__type__
return self is other
TypeGuard = _TypeGuard(_root=True)
if hasattr(typing, "Self"):
Self = typing.Self
elif sys.version_info[:2] >= (3, 7):
# Vendored from cpython typing._SpecialFrom
class _SpecialForm(typing._Final, _root=True):
__slots__ = ('_name', '__doc__', '_getitem')
def __init__(self, getitem):
self._getitem = getitem
self._name = getitem.__name__
self.__doc__ = getitem.__doc__
def __getattr__(self, item):
if item in {'__name__', '__qualname__'}:
return self._name
raise AttributeError(item)
def __mro_entries__(self, bases):
raise TypeError(f"Cannot subclass {self!r}")
def __repr__(self):
return f'typing_extensions.{self._name}'
def __reduce__(self):
return self._name
def __call__(self, *args, **kwds):
raise TypeError(f"Cannot instantiate {self!r}")
def __or__(self, other):
return typing.Union[self, other]
def __ror__(self, other):
return typing.Union[other, self]
def __instancecheck__(self, obj):
raise TypeError(f"{self} cannot be used with isinstance()")
def __subclasscheck__(self, cls):
raise TypeError(f"{self} cannot be used with issubclass()")
@typing._tp_cache
def __getitem__(self, parameters):
return self._getitem(self, parameters)
@_SpecialForm
def Self(self, params):
"""Used to spell the type of "self" in classes.
Example::
from typing import Self
class ReturnsSelf:
def parse(self, data: bytes) -> Self:
...
return self
"""
raise TypeError(f"{self} is not subscriptable")
else:
class _Self(typing._FinalTypingBase, _root=True):
"""Used to spell the type of "self" in classes.
Example::
from typing import Self
class ReturnsSelf:
def parse(self, data: bytes) -> Self:
...
return self
"""
__slots__ = ()
def __instancecheck__(self, obj):
raise TypeError(f"{self} cannot be used with isinstance().")
def __subclasscheck__(self, cls):
raise TypeError(f"{self} cannot be used with issubclass().")
Self = _Self(_root=True)
if hasattr(typing, 'Required'):
Required = typing.Required
NotRequired = typing.NotRequired
elif sys.version_info[:2] >= (3, 9):
class _ExtensionsSpecialForm(typing._SpecialForm, _root=True):
def __repr__(self):
return 'typing_extensions.' + self._name
@_ExtensionsSpecialForm
def Required(self, parameters):
"""A special typing construct to mark a key of a total=False TypedDict
as required. For example:
class Movie(TypedDict, total=False):
title: Required[str]
year: int
m = Movie(
title='The Matrix', # typechecker error if key is omitted
year=1999,
)
There is no runtime checking that a required key is actually provided
when instantiating a related TypedDict.
"""
item = typing._type_check(parameters, f'{self._name} accepts only single type')
return typing._GenericAlias(self, (item,))
@_ExtensionsSpecialForm
def NotRequired(self, parameters):
"""A special typing construct to mark a key of a TypedDict as
potentially missing. For example:
class Movie(TypedDict):
title: str
year: NotRequired[int]
m = Movie(
title='The Matrix', # typechecker error if key is omitted
year=1999,
)
"""
item = typing._type_check(parameters, f'{self._name} accepts only single type')
return typing._GenericAlias(self, (item,))
elif sys.version_info[:2] >= (3, 7):
class _RequiredForm(typing._SpecialForm, _root=True):
def __repr__(self):
return 'typing_extensions.' + self._name
def __getitem__(self, parameters):
item = typing._type_check(parameters,
'{} accepts only single type'.format(self._name))
return typing._GenericAlias(self, (item,))
Required = _RequiredForm(
'Required',
doc="""A special typing construct to mark a key of a total=False TypedDict
as required. For example:
class Movie(TypedDict, total=False):
title: Required[str]
year: int
m = Movie(
title='The Matrix', # typechecker error if key is omitted
year=1999,
)
There is no runtime checking that a required key is actually provided
when instantiating a related TypedDict.
""")
NotRequired = _RequiredForm(
'NotRequired',
doc="""A special typing construct to mark a key of a TypedDict as
potentially missing. For example:
class Movie(TypedDict):
title: str
year: NotRequired[int]
m = Movie(
title='The Matrix', # typechecker error if key is omitted
year=1999,
)
""")
else:
# NOTE: Modeled after _Final's implementation when _FinalTypingBase available
class _MaybeRequired(typing._FinalTypingBase, _root=True):
__slots__ = ('__type__',)
def __init__(self, tp=None, **kwds):
self.__type__ = tp
def __getitem__(self, item):
cls = type(self)
if self.__type__ is None:
return cls(typing._type_check(item,
'{} accepts only single type.'.format(cls.__name__[1:])),
_root=True)
raise TypeError('{} cannot be further subscripted'
.format(cls.__name__[1:]))
def _eval_type(self, globalns, localns):
new_tp = typing._eval_type(self.__type__, globalns, localns)
if new_tp == self.__type__:
return self
return type(self)(new_tp, _root=True)
def __repr__(self):
r = super().__repr__()
if self.__type__ is not None:
r += '[{}]'.format(typing._type_repr(self.__type__))
return r
def __hash__(self):
return hash((type(self).__name__, self.__type__))
def __eq__(self, other):
if not isinstance(other, type(self)):
return NotImplemented
if self.__type__ is not None:
return self.__type__ == other.__type__
return self is other
class _Required(_MaybeRequired, _root=True):
"""A special typing construct to mark a key of a total=False TypedDict
as required. For example:
class Movie(TypedDict, total=False):
title: Required[str]
year: int
m = Movie(
title='The Matrix', # typechecker error if key is omitted
year=1999,
)
There is no runtime checking that a required key is actually provided
when instantiating a related TypedDict.
"""
class _NotRequired(_MaybeRequired, _root=True):
"""A special typing construct to mark a key of a TypedDict as
potentially missing. For example:
class Movie(TypedDict):
title: str
year: NotRequired[int]
m = Movie(
title='The Matrix', # typechecker error if key is omitted
year=1999,
)
"""
Required = _Required(_root=True)
NotRequired = _NotRequired(_root=True)
|