How can one get the value of a vector Constant?

Question

For a scalar valued Constant object one can simply call float to get the value

a = Constant(1.0)

print float(a)

1.0

but for a vector the situation is a little more tricky

a = Constant([1.0,1.0])
print [float(item) for item in a]

TypeError: float returned non-float (type Indexed)

Does anyone have a way to get the values out of the vector Constant?

Comments

I was being driven mad looking for this exactly-- print float(a)

My question: If I hadnt found your post, how could I have realized what is the command to print the value of a Constant object ?
I could not figure this out from the documentation or by examining the output of dir(a)

Answer 1

import numpy as np
vals = np.zeros(2)
a.eval(vals, np.zeros(3))
print vals

You also can request an ehancement of Constant interface.

Comments

Thanks Jan,
Your answer works ;-)