nDimensional sparse histogram in python.

[rajasekaran.natarajan at gmail.com]

Hi
you can use has_key() to check whether
the particular value is in the key set or not.

>>> a = {}
>>> a[1] = 22
>>> a[2] = 33
>>> a
{1: 22, 2: 33}
>>> a.has_key(3)
False
>>> a.has_key(1)
True
>>>


-raj
KraftDiner wrote:
> Ok so this is nice.. Just one thing.. When you try to get a value from
> a dictionary
> and it isn't found in the dictionary things go bad...
>
> Take this for example:
>
> class histogram(object):
> 	def __init__(self):
> 		self.histo = {}
>
> 	def update(self, point):
> 		if self.histo.get(point) != None:
> 			self.histo[point] = self.histo[point] + 1
> 		else:
> 			self.histo[point] = 1
>
> 	def get(self, point):
> 		return self.histo[point]
>
>
> hist = histogram()
> hist.update((0,0,0))
> hist.update((0,0,1))
> hist.update((0,0,1))
> hist.get((0,0,0))
> hist.get((0,0,1))
> hist.get((0,0,2))
>
> spews out this error:
>
> Traceback (most recent call last):
>   File "histogram.py", line 21, in ?
>     hist.get((0,0,2))
>   File "histogram.py", line 12, in get
>     return self.histo[point]
> KeyError: (0, 0, 2)