Convert list or numpy array of single element to float in python

Question

I have a function which can accept either a list or a numpy array.

In either case, the list/array has a single element (always). I just need to return a float.

Answer 1

Just access the first item of the list/array, using the index access and the index 0:

>>> list_ = [4]
>>> list_[0]
4
>>> array_ = np.array([4])
>>> array_[0]
4

This will be an int since that was what you inserted in the first place. If you need it to be a float for some reason, you can call float() on it then:

>>> float(list_[0])
4.0