Issue #17941: Add a *module* parameter to collections.namedtuple()

This commit is contained in:
Raymond Hettinger 2016-09-12 00:18:31 -07:00
parent 11fa3ffcb1
commit 0d5048cb21
4 changed files with 22 additions and 7 deletions

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@ -763,7 +763,7 @@ Named tuples assign meaning to each position in a tuple and allow for more reada
self-documenting code. They can be used wherever regular tuples are used, and
they add the ability to access fields by name instead of position index.
.. function:: namedtuple(typename, field_names, *, verbose=False, rename=False)
.. function:: namedtuple(typename, field_names, *, verbose=False, rename=False, module=None)
Returns a new tuple subclass named *typename*. The new subclass is used to
create tuple-like objects that have fields accessible by attribute lookup as
@ -790,6 +790,9 @@ they add the ability to access fields by name instead of position index.
built. This option is outdated; instead, it is simpler to print the
:attr:`_source` attribute.
If *module* is defined, the ``__module__`` attribute of the named tuple is
set to that value.
Named tuple instances do not have per-instance dictionaries, so they are
lightweight and require no more memory than regular tuples.
@ -800,6 +803,8 @@ they add the ability to access fields by name instead of position index.
The *verbose* and *rename* parameters became
:ref:`keyword-only arguments <keyword-only_parameter>`.
.. versionchanged:: 3.6
Added the *module* parameter.
.. doctest::
:options: +NORMALIZE_WHITESPACE

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@ -353,7 +353,7 @@ _field_template = '''\
{name} = _property(_itemgetter({index:d}), doc='Alias for field number {index:d}')
'''
def namedtuple(typename, field_names, *, verbose=False, rename=False):
def namedtuple(typename, field_names, *, verbose=False, rename=False, module=None):
"""Returns a new subclass of tuple with named fields.
>>> Point = namedtuple('Point', ['x', 'y'])
@ -434,11 +434,15 @@ def namedtuple(typename, field_names, *, verbose=False, rename=False):
# For pickling to work, the __module__ variable needs to be set to the frame
# where the named tuple is created. Bypass this step in environments where
# sys._getframe is not defined (Jython for example) or sys._getframe is not
# defined for arguments greater than 0 (IronPython).
try:
result.__module__ = _sys._getframe(1).f_globals.get('__name__', '__main__')
except (AttributeError, ValueError):
pass
# defined for arguments greater than 0 (IronPython), or where the user has
# specified a particular module.
if module is None:
try:
module = _sys._getframe(1).f_globals.get('__name__', '__main__')
except (AttributeError, ValueError):
pass
if module is not None:
result.__module__ = module
return result

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@ -242,6 +242,10 @@ class TestNamedTuple(unittest.TestCase):
]:
self.assertEqual(namedtuple('NT', spec, rename=True)._fields, renamed)
def test_module_parameter(self):
NT = namedtuple('NT', ['x', 'y'], module=collections)
self.assertEqual(NT.__module__, collections)
def test_instance(self):
Point = namedtuple('Point', 'x y')
p = Point(11, 22)

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@ -159,6 +159,8 @@ Library
- Issue #10740: sqlite3 no longer implicitly commit an open transaction
before DDL statements.
- Issue #17941: Add a *module* parameter to collections.namedtuple().
- Issue #22493: Inline flags now should be used only at the start of the
regular expression. Deprecation warning is emitted if uses them in the
middle of the regular expression.