# funcionvaloresdefecto.py
def myfunc(a=4,b=6):
    sum = a + b
    return sum
print myfunc() # 4+6 = 10
print myfunc(b=8) # 12
print myfunc(a=3) # 9
print myfunc(3, 4) # 7
print myfunc(b=1, a=12) # 13