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Merged
ilevkivskyi merged 3 commits into from
Nov 24, 2019
Merged

Accept arbitrary keyword names in NamedTuple() and TypedDict() #686

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8fabafd
Accept arbitrary keyword names in NamedTuple() and TypedDict()
Nov 23, 2019
1b114b0
Fix tests
Nov 23, 2019
05119ff
Fix lint
Nov 23, 2019
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32 changes: 32 additions & 0 deletions src/test_typing.py
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Original file line number Diff line number Diff line change
Expand Up @@ -2513,6 +2513,38 @@ def test_namedtuple_keyword_usage(self):
with self.assertRaises(TypeError):
NamedTuple('Name', x=1, y='a')

@skipUnless(PY36, 'Python 3.6 required')
def test_namedtuple_special_keyword_names(self):
NT = NamedTuple("NT", cls=type, self=object, typename=str, fields=list)
self.assertEqual(NT.__name__, 'NT')
self.assertEqual(NT._fields, ('cls', 'self', 'typename', 'fields'))
a = NT(cls=str, self=42, typename='foo', fields=[('bar', tuple)])
self.assertEqual(a.cls, str)
self.assertEqual(a.self, 42)
self.assertEqual(a.typename, 'foo')
self.assertEqual(a.fields, [('bar', tuple)])

@skipUnless(PY36, 'Python 3.6 required')
def test_namedtuple_errors(self):
with self.assertRaises(TypeError):
NamedTuple.__new__()
with self.assertRaises(TypeError):
NamedTuple()
with self.assertRaises(TypeError):
NamedTuple('Emp', [('name', str)], None)
with self.assertRaises(ValueError):
NamedTuple('Emp', [('_name', str)])

with self.assertWarns(DeprecationWarning):
Emp = NamedTuple(typename='Emp', name=str, id=int)
self.assertEqual(Emp.__name__, 'Emp')
self.assertEqual(Emp._fields, ('name', 'id'))

with self.assertWarns(DeprecationWarning):
Emp = NamedTuple('Emp', fields=[('name', str), ('id', int)])
self.assertEqual(Emp.__name__, 'Emp')
self.assertEqual(Emp._fields, ('name', 'id'))

def test_pickle(self):
global Emp # pickle wants to reference the class by name
Emp = NamedTuple('Emp', [('name', str), ('id', int)])
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32 changes: 31 additions & 1 deletion src/typing.py
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Expand Up @@ -2204,17 +2204,47 @@ class Employee(NamedTuple):
"""
_root = True

def __new__(self, typename, fields=None, **kwargs):
def __new__(*args, **kwargs):
if kwargs and not _PY36:
raise TypeError("Keyword syntax for NamedTuple is only supported"
" in Python 3.6+")
if not args:
raise TypeError('NamedTuple.__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("NamedTuple.__new__() missing 1 required positional "
"argument: 'typename'")
if args:
try:
fields, = args # allow the "fields" keyword be passed
except ValueError:
raise TypeError('NamedTuple.__new__() takes from 2 to 3 '
'positional arguments but {} '
'were given'.format(len(args) + 2))
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.items()
elif kwargs:
raise TypeError("Either list of fields or keywords"
" can be provided to NamedTuple, not both")
return _make_nmtuple(typename, fields)

__new__.__text_signature__ = '($cls, typename, fields=None, /, **kwargs)'


def NewType(name, tp):
"""NewType creates simple unique types with almost zero
Expand Down
36 changes: 35 additions & 1 deletion typing_extensions/src_py3/test_typing_extensions.py
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Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@
import pickle
import subprocess
import types
from unittest import TestCase, main, skipUnless
from unittest import TestCase, main, skipUnless, skipIf
from typing import TypeVar, Optional
from typing import T, KT, VT # Not in __all__.
from typing import Tuple, List, Dict, Iterator
Expand Down Expand Up @@ -1445,6 +1445,40 @@ def test_basics_keywords_syntax(self):
self.assertEqual(Emp.__annotations__, {'name': str, 'id': int})
self.assertEqual(Emp.__total__, True)

def test_typeddict_special_keyword_names(self):
TD = TypedDict("TD", cls=type, self=object, typename=str, _typename=int,
fields=list, _fields=dict)
self.assertEqual(TD.__name__, 'TD')
self.assertEqual(TD.__annotations__, {'cls': type, 'self': object, 'typename': str,
'_typename': int, 'fields': list, '_fields': dict})
a = TD(cls=str, self=42, typename='foo', _typename=53,
fields=[('bar', tuple)], _fields={'baz', set})
self.assertEqual(a['cls'], str)
self.assertEqual(a['self'], 42)
self.assertEqual(a['typename'], 'foo')
self.assertEqual(a['_typename'], 53)
self.assertEqual(a['fields'], [('bar', tuple)])
self.assertEqual(a['_fields'], {'baz', set})

@skipIf(hasattr(typing, 'TypedDict'), "Should be tested by upstream")
def test_typeddict_create_errors(self):
with self.assertRaises(TypeError):
TypedDict.__new__()
with self.assertRaises(TypeError):
TypedDict()
with self.assertRaises(TypeError):
TypedDict('Emp', [('name', str)], None)

with self.assertWarns(DeprecationWarning):
Emp = TypedDict(_typename='Emp', name=str, id=int)
self.assertEqual(Emp.__name__, 'Emp')
self.assertEqual(Emp.__annotations__, {'name': str, 'id': int})

with self.assertWarns(DeprecationWarning):
Emp = TypedDict('Emp', _fields={'name': str, 'id': int})
self.assertEqual(Emp.__name__, 'Emp')
self.assertEqual(Emp.__annotations__, {'name': str, 'id': int})

def test_typeddict_errors(self):
Emp = TypedDict('Emp', {'name': str, 'id': int})
if hasattr(typing, 'TypedDict'):
Expand Down
49 changes: 42 additions & 7 deletions typing_extensions/src_py3/typing_extensions.py
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Expand Up @@ -1583,25 +1583,60 @@ def _check_fails(cls, other):
pass
return False

def _dict_new(cls, *args, **kwargs):
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)

def _typeddict_new(cls, _typename, _fields=None, **kwargs):
total = kwargs.pop('total', True)
if _fields is None:
_fields = 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 '
'positional arguments but {} '
'were given'.format(len(args) + 2))
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), '__total__': total}
ns = {'__annotations__': dict(fields), '__total__': total}
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)
return _TypedDictMeta(typename, (), ns)

_typeddict_new.__text_signature__ = ('($cls, _typename, _fields=None,'
' /, *, total=True, **kwargs)')

class _TypedDictMeta(type):
def __new__(cls, name, bases, ns, total=True):
Expand Down