kth-largest-element-in-array throws Exceptions for edge cases

The given solution in Python throws a TypeError for the given example and IndexError for other examples. A couple of suggested changes:

1. Use integer division in line 13
2. Adjust k only once

Something like this:

def kth_largest(l, k):
    """
    Shorthand Quicksort
    Runtime: O(n * log n)
    """
    # kth largest element
    # is k-1th element in output
    def qsort(arr, pos):
        middle = len(arr)//2
        pivot = arr[middle]
        smaller = [i for i in arr if i < pivot]
        if pos < len(smaller):
            return qsort(smaller, pos)
        equal = [i for i in arr if i == pivot]
        if pos < len(smaller) + len(equal):
            return pivot
        larger = [i for i in arr if i > pivot]
        return qsort(larger, pos - len(smaller) - len(equal))

    return qsort(l, k-1)