How is it supposed to work with set or dict or other iterables without clear order?
see the discussion in another recent thread about making dict indexable -- which looks like it's not going to happen.
so no -- this should not work with general iterables, indexes don't really make sense for iterables, only Sequences.
Is your use of such a function so performance sensitive that you need this in C?
Have you considered writing this as a C extension for your own use?
or use numpy :-) (which is probably where the name "argmin" came from, rather than "index_min")
Signature: np.argmin(a, axis=None, out=None)
Docstring:
Returns the indices of the minimum values along an axis.
Parameters
----------
a : array_like
Input array.
axis : int, optional
By default, the index is into the flattened array, otherwise
along the specified axis.
out : array, optional
If provided, the result will be inserted into this array. It should
be of the appropriate shape and dtype.
Returns
-------
index_array : ndarray of ints
Array of indices into the array. It has the same shape as `a.shape`
with the dimension along `axis` removed
The other question of course, is what to do when the minimum value appears more than once -- numpy appears to give the first occurance:
In [6]: np.argmin([3,2,1,2,3,4,5,1,2,3])
Out[6]: 2
-CHB