Question

I need to access variables given their names, in the following way:

a = numpy.array([1,2,3])
b = numpy.array([4,5,6])
names = ('a', 'b')

Then, I pass the variable names to a function, say numpy.hstack() to obtain the same result as with numpy.hstack((a,b)).

What is the best pythonic way to do so?

And what is the purpose? I have a function, that accepts names of numpy arrays and stacks the related arrays (defined in the function) together to process them. I need to create all possible combinations of these arrays, hence:

1. A combination (tuple) of array names is created.
2. The combination (tuple) is passed to a function as an argument.
3. The function concatenates related arrays and processes the result.

Hopefully this question is not too cryptic. Thanks for responses in advance 🙂

Answer 1

You can use the built-in function locals, which returns a dictionary representing the local namespace:

>>> a = 1
>>> locals()['a']
1

>>> a = 1; b = 2; c = 3
>>> [locals()[x] for x in ('a','b','c')]
[1, 2, 3]

You could also simply store your arrays in your own dictionary, or in a module.