Language Basics Python

import sys
import string
def julian_leap(y=2000):
    if (y%4) == 0:
        return 1
    return 0
def gregorian_leap(y=2000):
    if (y%400) == 0:
         return 1
    elif (y%100) == 0:
         return 0
    elif (y%4) == 0:
         return 1
    return 0
 years = [1999,2000,2001,1900]
 print julian_leap()
 print gregorian_leap()
 if julian_leap():
     print "Julian 2000 yes"
 if gregorian_leap():
     print "Gregorian 2000 yes"
 for x in years:
     if julian_leap(x):
         print "Julian", x, "is leap"
     else:
         print "Julian", x, "is not leap"
     if gregorian_leap(x):
         print "Gregorian", x, "is leap"
     else:
         print "Gregorian", x, "is not leap"