#Why does it matter where my: print num_ly(1900,2000)is located?  I thought once we wrote it that we could call on it anywhere in out #code?

#for example, this works:

def num_ly(year1, year2):
    n = 0
    while year1 < year2:
        print year1
        if isleap(year1):
            n = n + 1
            print n
        year1 = year1 +1

def isleap(year1):
    return year1 % 4 == 0 and (year1 % 100 != 0 or year1 % 400 == 0)

print num_ly(1900,2000)

#but this doesn't:

def num_ly(year1, year2):
    n = 0
    while year1 < year2:
        print year1
        if isleap(year1):
            n = n + 1
            print n
        year1 = year1 +1

print num_ly(1900,2000)

def isleap(year1):
    return year1 % 4 == 0 and (year1 % 100 != 0 or year1 % 400 == 0)