views:

59

answers:

2

hi there, are there any way to create an object form any class inside a numpy array?. Something like:

a = zeros(4)

for i in range(4):
   a[i]=Register()

Thanks

A: 

Yes, you can do this:

a = numpy.array([Register() for _ in range(4)])

Here, a.dtype is dtype('object').

Alternatively, if you really need to reserve memory for your array and then build it element by element, you can do:

a = numpy.empty(shape=(4,), dtype=object)
a[0] = Register()  # etc.
EOL
@Mike: thank you for spotting the typo in the first solution; what I meant was of course what you put in your solution. I had forgotten to build the list first; it's now corrected. For the second solution, I switched to numpy.empty.
EOL
A: 

The items in numpy arrays are statically typed, and when you call zeros you make an array of floats. To store arbitrary Python objects, use code like

numpy.array([Register() for i in xrange(4)])

which makes an array with dtype=object, which you could also specify manually.

Consider whether you really want numpy in this case. I don't know how close this example is to your use case, but oftentimes a numpy array of dtype object, especially a one-dimensional one, would work at least as well as a list.

Mike Graham