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Cleaner method naming convention
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3 changed files with 30 additions and 30 deletions
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@ -368,8 +368,8 @@ they add the ability to access fields by name instead of position index.
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can be specified as a list of strings (such as ['x', 'y']).
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Any valid Python identifier may be used for a fieldname except for names
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starting and ending with double underscores. Valid identifiers consist of
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letters, digits, and underscores but do not start with a digit and cannot be
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starting with an underscore. Valid identifiers consist of letters, digits,
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and underscores but do not start with a digit or underscore and cannot be
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a :mod:`keyword` such as *class*, *for*, *return*, *global*, *pass*, *print*,
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or *raise*.
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@ -386,15 +386,15 @@ Example::
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class Point(tuple):
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'Point(x, y)'
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__slots__ = ()
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__fields__ = ('x', 'y')
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_fields = ('x', 'y')
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def __new__(cls, x, y):
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return tuple.__new__(cls, (x, y))
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def __repr__(self):
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return 'Point(x=%r, y=%r)' % self
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def __asdict__(self):
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def _asdict(self):
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'Return a new dict mapping field names to their values'
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return dict(zip(('x', 'y'), self))
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def __replace__(self, **kwds):
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def _replace(self, **kwds):
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'Return a new Point object replacing specified fields with new values'
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return Point(**dict(zip(('x', 'y'), self), **kwds))
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x = property(itemgetter(0))
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@ -444,40 +444,40 @@ When casting a dictionary to a named tuple, use the double-star-operator::
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In addition to the methods inherited from tuples, named tuples support
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two additonal methods and a read-only attribute.
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.. method:: somenamedtuple.__asdict__()
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.. method:: somenamedtuple._asdict()
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Return a new dict which maps field names to their corresponding values:
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::
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>>> p.__asdict__()
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>>> p._asdict()
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{'x': 11, 'y': 22}
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.. method:: somenamedtuple.__replace__(kwargs)
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.. method:: somenamedtuple._replace(kwargs)
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Return a new instance of the named tuple replacing specified fields with new values:
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::
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>>> p = Point(x=11, y=22)
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>>> p.__replace__(x=33)
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>>> p._replace(x=33)
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Point(x=33, y=22)
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>>> for partnum, record in inventory.items():
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... inventory[partnum] = record.__replace__(price=newprices[partnum], updated=time.now())
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... inventory[partnum] = record._replace(price=newprices[partnum], updated=time.now())
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.. attribute:: somenamedtuple.__fields__
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.. attribute:: somenamedtuple._fields
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Return a tuple of strings listing the field names. This is useful for introspection
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and for creating new named tuple types from existing named tuples.
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::
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>>> p.__fields__ # view the field names
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>>> p._fields # view the field names
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('x', 'y')
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>>> Color = namedtuple('Color', 'red green blue')
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>>> Pixel = namedtuple('Pixel', Point.__fields__ + Color.__fields__)
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>>> Pixel = namedtuple('Pixel', Point._fields + Color._fields)
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>>> Pixel(11, 22, 128, 255, 0)
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Pixel(x=11, y=22, red=128, green=255, blue=0)'
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@ -493,13 +493,13 @@ the :meth:`__repr__` method:
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Point(10.000, 20.000)
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Default values can be implemented by starting with a prototype instance
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and customizing it with :meth:`__replace__`:
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and customizing it with :meth:`_replace`:
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::
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>>> Account = namedtuple('Account', 'owner balance transaction_count')
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>>> model_account = Account('<owner name>', 0.0, 0)
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>>> johns_account = model_account.__replace__(owner='John')
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>>> johns_account = model_account._replace(owner='John')
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.. rubric:: Footnotes
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