if test1:
action1_block
elif test2:
action2_block
elif test3:
action3_block
else:
else_action_block
def ticket_cost(age):
if age < 3:
cost = 0.0
elif age < 18:
cost = 5.50
elif age < 65:
cost = 9.25
else:
cost = 8.00
return cost
## factorial(x) produces the product ## of all the integers from 1 to n ## factorial: Nat -> Nat
## example:
## factorial(5) => 120 ## factorial(0) => 1
def factorial (x):
if x == 0:
return 1
else:
return x * factorial( x - 1)
factorial(1000) -> RuntimeError: maximum recursion depth exceeded
If a function does not include a return statement, then the produced value (and type) is None