def is_leap(year):
 x = math.fmod(year, 4)
 y = math.fmod(year, 100)
 z = math.fmod(year, 400)
 return ((not x) and (y or (not z)))

def is_leap ( year ) : x = math . fmod ( year , 4 ) y = math . fmod ( year , 100 ) z = math . fmod ( year , 400 ) return ( ( not x ) and ( y or ( not z ) ) )
leap year or not in the gregorian calendar .