Question

Without any heavy libraries such as numpy, I want to uniformly handle a single list or multi-dimensional list in my code. For example, the function sum_up(list_or_matrix) should
return 6 for argument [1, 2, 3] and return 9 for [[1, 2, 3], [1, 2, 0]].

My question is:
1. Can I code in a way without explicitly detecting the dimension of my input such as by isinstance(arg[0], (tuple, list))?

2. If I have to do so, is there any elegant way of detecting the dimension of a list (of list of list …), e.g. recursively?

Answer 1

As many users suggested you can always use dict instead of list for any-dimensinal collection. Dictionaries are accepting tuples as arguments as they are hashable. So you can easy fill-up your collection like

>>> m = {}
>>> m[1] = 1
>>> m[1,2] = 12
>>> m[1,2,"three",4.5] = 12345
>>> sum(m.values()) #better use m.itervalues() in python 2.* 
12358