You want a loop. Try something like this:
def julian_leap (y) :
if (y%4) == 0:
return 1
return 0
Except in reality, leap year is not quite so simple
as "every fourth year".
Something like:
def julian_leap (y) :
rtnval = 0
if (y%100)==0:
if (y%400)==0:
rtnval = 1
elif (y%4) == 0:
rtnval = 1
return rtnval
1900 was not a leap year.
Kirby