How to convert Python dictionary object to numpy array
I have python dict object with key as datetime.date object and values as tuple objects:
>>> data_d开发者_StackOverflowict
{datetime.date(2006, 1, 1): (5, 3),
datetime.date(2006, 1, 2): (8, 8),
datetime.date(2006, 1, 3): (8, 5),
datetime.date(2006, 1, 4): (3, 3),
datetime.date(2006, 1, 5): (3, 3),
datetime.date(2006, 1, 6): (4, 3),
...
and I want to convert it to numpy array object in this format:
dtype([('date', '|O4'), ('high', '<i1'), ('low', '<i1')])
so that I could store it on disk and later work with it, and learn, in numpy, matplotlib...
As a matter of fact, I thought to use this format after looking at this matplotlib examples: http://matplotlib.sourceforge.net/users/recipes.html but can't find my way out how to get there.
The following will do it:
arr = np.array([(k,)+v for k,v in data_dict.iteritems()], \
dtype=[('date', '|O4'), ('high', '<f8'), ('low', '<f8')])
If you then wish to use arr
as a recarray
, you could use:
arr = arr.view(np.recarray)
This will enable you to reference fields by name, e.g. arr.date
.
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