See http://bicycles.stackexchange.com/q/24460/10492 and http://codereview.stackexchange.com/q/61656/32391

race.py

import datetime
from operator import itemgetter

def get_int_input(prompt, min_=0, max_=None):
    """Get a valid integer input."""
    while True:
        try:
            i = int(input(prompt))
        except ValueError:
            print("Please enter an integer.")
        else:
            if min_ is not None and i < min_:
                print("Must be at least {0}.".format(min_))
                continue
            elif max_ is not None and i > max_:
                print("Must be at most {0}.".format(max_))
                continue
            return i

def get_time():
    """"Get a time input as a datetime.time object."""
    h = get_int_input("Hours (0-23): ", max_=23)
    m = get_int_input("Minutes (0-59): ", max_=59)
    s = get_int_input("Seconds (0-59): ", max_=59)
    ms = get_int_input("Milliseconds (0-999): ", max_=999)
    return datetime.time(h, m, s, ms*1000)

def get_results(competitors):
    """Get a dict of finishing times for all competitors."""
    results = {}
    for _ in range(competitors):
        while True:
            competitor = get_int_input("Enter competitor number: ", min_=1, 
                                       max_=competitors+1)
            if competitor not in results:
                results[competitor] = get_time()
                break
            print("Time already entered.")
    return results

def print_results(results):
    """Display the race results in a table, fastest first."""
    line = "-" * 32
    print(line)
    print("| Competitor | Time (H:M:S)    |")
    for n, t in sorted(results.items(), key=itemgetter(1)):
        print(line)
        print("| {0:<10d} | {1!s:<15} |".format(n, t))
    print(line)

def race():
    """Handle race times for a user-specified number of competitors."""
    n = get_int_input("Enter number of competitors (2-): ", min_=2)
    results = get_results(n)
    print_results(results)

if __name__ == "__main__":
    race()