I'm thinking if there is some way to unpack object attributes. Usually doing this involves series of:
self.x = x
self.y = y
... #etc.
However it should be possible to do it better.
I'm thinking about something like:
def __init__(self,x,y,z):
self.(x,y,z) = x,y,z
or maybe:
with x,y,z unpack(self)
or even function like:
def __init__(self,x,y,z):
unpack(self,x,y,z)
Any ideas? Or is there some more pythonic way to do this?
You might want to use namedtuple
, which does exactly the thing you want:
Code example from Official Python Documentation:
Point = namedtuple('Point', ['x', 'y'], verbose=True)
The above code is equivalent to:
class Point(tuple):
'Point(x, y)'
__slots__ = ()
_fields = ('x', 'y')
def __new__(_cls, x, y):
'Create a new instance of Point(x, y)'
return _tuple.__new__(_cls, (x, y))
@classmethod
def _make(cls, iterable, new=tuple.__new__, len=len):
'Make a new Point object from a sequence or iterable'
result = new(cls, iterable)
if len(result) != 2:
raise TypeError('Expected 2 arguments, got %d' % len(result))
return result
def __repr__(self):
'Return a nicely formatted representation string'
return 'Point(x=%r, y=%r)' % self
def _asdict(self):
'Return a new OrderedDict which maps field names to their values'
return OrderedDict(zip(self._fields, self))
def _replace(_self, **kwds):
'Return a new Point object replacing specified fields with new values'
result = _self._make(map(kwds.pop, ('x', 'y'), _self))
if kwds:
raise ValueError('Got unexpected field names: %r' % kwds.keys())
return result
def __getnewargs__(self):
'Return self as a plain tuple. Used by copy and pickle.'
return tuple(self)
__dict__ = _property(_asdict)
def __getstate__(self):
'Exclude the OrderedDict from pickling'
pass
x = _property(_itemgetter(0), doc='Alias for field number 0')
y = _property(_itemgetter(1), doc='Alias for field number 1')
Here's how to use it:
>>> p = Point(11, y=22) # instantiate with positional or keyword arguments
>>> p[0] + p[1] # indexable like the plain tuple (11, 22)
33
>>> x, y = p # unpack like a regular tuple
>>> x, y
(11, 22)
>>> p.x + p.y # fields also accessible by name
33
>>> p # readable __repr__ with a name=value style
Point(x=11, y=22)
Source: http://docs.python.org/2/library/collections.html#namedtuple-factory-function-for-tuples-with-named-fields
One thing worth mentioning is that namedtuple
is nothing but a regular class, and you could create a class that inherit from it.
I am pretty sure that you can do this: self.x, self.y, self.z = x, y, z
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