mirror of
https://github.com/python/cpython.git
synced 2025-11-04 11:49:12 +00:00
68 lines
2.2 KiB
Python
68 lines
2.2 KiB
Python
__all__ = ['deque', 'defaultdict', 'NamedTuple']
|
|
|
|
from _collections import deque, defaultdict
|
|
from operator import itemgetter as _itemgetter
|
|
import sys as _sys
|
|
|
|
# For bootstrapping reasons, the collection ABCs are defined in _abcoll.py.
|
|
# They should however be considered an integral part of collections.py.
|
|
from _abcoll import *
|
|
import _abcoll
|
|
__all__ += _abcoll.__all__
|
|
|
|
|
|
def NamedTuple(typename, s):
|
|
"""Returns a new subclass of tuple with named fields.
|
|
|
|
>>> Point = NamedTuple('Point', 'x y')
|
|
>>> Point.__doc__ # docstring for the new class
|
|
'Point(x, y)'
|
|
>>> p = Point(11, y=22) # instantiate with positional args or keywords
|
|
>>> p[0] + p[1] # works just like the tuple (11, 22)
|
|
33
|
|
>>> x, y = p # unpacks just like a tuple
|
|
>>> x, y
|
|
(11, 22)
|
|
>>> p.x + p.y # fields also accessable by name
|
|
33
|
|
>>> p # readable __repr__ with name=value style
|
|
Point(x=11, y=22)
|
|
|
|
"""
|
|
|
|
field_names = s.split()
|
|
if not ''.join([typename] + field_names).replace('_', '').isalnum():
|
|
raise ValueError('Type names and field names can only contain alphanumeric characters and underscores')
|
|
argtxt = ', '.join(field_names)
|
|
reprtxt = ', '.join('%s=%%r' % name for name in field_names)
|
|
template = '''class %(typename)s(tuple):
|
|
'%(typename)s(%(argtxt)s)'
|
|
__slots__ = ()
|
|
def __new__(cls, %(argtxt)s):
|
|
return tuple.__new__(cls, (%(argtxt)s,))
|
|
def __repr__(self):
|
|
return '%(typename)s(%(reprtxt)s)' %% self
|
|
''' % locals()
|
|
for i, name in enumerate(field_names):
|
|
template += '\n %s = property(itemgetter(%d))\n' % (name, i)
|
|
m = dict(itemgetter=_itemgetter)
|
|
exec(template, m)
|
|
result = m[typename]
|
|
if hasattr(_sys, '_getframe'):
|
|
result.__module__ = _sys._getframe(1).f_globals['__name__']
|
|
return result
|
|
|
|
|
|
|
|
|
|
|
|
if __name__ == '__main__':
|
|
# verify that instances are pickable
|
|
from pickle import loads, dumps
|
|
Point = NamedTuple('Point', 'x y')
|
|
p = Point(x=10, y=20)
|
|
assert p == loads(dumps(p))
|
|
|
|
import doctest
|
|
TestResults = NamedTuple('TestResults', 'failed attempted')
|
|
print(TestResults(*doctest.testmod()))
|