Minimalistic Merge sort in Python

mergesort.py

def select(left, right):
    """Choose the minimum front from left and right, but handle empty lists."""
    return left.pop(0) if (len(left) > 0 and len(right) is 0) or (len(left) > 0 and left[0] < right[0]) else right.pop(0)

def merge(left, right):
    """Conquer: Merge together the selected (min) front of left and right."""
    return [select(left,right) for i in range((len(left) + len(right)))]

def sort(l):
    """Divide: Recursive call to split input list into managable sublists."""
    return l if len(l) is 1 else merge(sort(l[:len(l)/2]), sort(l[len(l)/2:]))

if __name__ == '__main__':
    l = list("aninputstring")           # string list
    l = [int(s) for s in "8234837"]     # integer list
    print sort(l)

This is short, well done! I need to get back into python.

Maybe I'll make a haskell equivalent for fun.