A small python function to quicksort any list from smallest to largest. Now using the correct division operator "//".

quicksort.py

def quicksort(p_list):
    """
    Quicksort using comprehension and recursion on a list.
    """
    if len(p_list) < 1:
        return p_list

    center = p_list[len(p_list) // 2]
    centers = [x for x in p_list if x == center]
    smaller = quicksort([x for x in p_list if x < center])
    larger = quicksort([x for x in p_list if x > center])
    return smaller + centers + larger


def main():
    nums = [14, 567, 3345, 34553, 2454, 29, 55, 6, 87, 123, 21312, 199,
            546, 568, 78, 987, 234234, 15, 7, 657, 25, 2, 234, 64, 35, 6544, 1]
    print (quicksort(nums))
    pass


if __name__ == '__main__':
    main()

You need to convert
center=p_list[len(p_list)/2]
to
center=p_list[int(len(p_list)/2)]

You need to convert the center to int.
List indices must be integers or slices, not float. Your code give an error, because when you divide a number the result has a decimal point.

@RyukGremory Thank you!
Your observation is correct for Python3.x I developed this in Python2.7 and it works fine there :)

The explanation is that Python3 uses "/" as a float division, Python2 uses "/" as an integer division. Your suggested change would make the code work in both versions.

Using // is better I think. The intent is to force an integer division, regardless of the Python version.