two simple questions about arrays

[jenya56]

Dear all:
1.) how to initilize numpy array? I need something similar to:
data = []
2.) how to add elements to nested lists?
I have list a:
a= [[1 2][1 2 3 3]]
how to append something to a[0]
THANKS SO MUCH.

[bvdet]

>>> numpy.zeros(10)
array([ 0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.])
>>> a= [[1, 2],[1, 2, 3, 3]]
>>> a[0].append('something')
>>> a
[[1, 2, 'something'], [1, 2, 3, 3]]
>>>

[jenya56]

but here you assume you know the size of your array

I do not know the size....

[bvdet]

OK, then how about:

>>> numpy.zeros(0)
array([], dtype=float64)
>>>

[jenya56]

THANK YOU so much....

[jenya56]

Hi, I was wondering if you could help me again....How do I add something to numpy array? Say I have :
>>> a= numpy.zeros(0)
Then I want to start adding elements to a. By the end I want a to look something like this a=[[1, 2], [4]]. I have no problem doing it with the actual python lists.

[bvdet]

Perhaps you should read the numpy documentation.