Exercises - generated recursively

Generator expressions
exercises a

def demo():
    for i in range(4):
        yield i

g=demo()

g1=(i for i in g)
g2=(i for i in g1)

print(list(g1))
print(list(g2))

Two exercises

def add(n,i):
    return n+i

def test():
    for i in range(4):
        yield i

g=test()
for n in [1,10]:
    g=(add(n,i) for i in g)

print(list(g))

recursive function

Exercises:

1, 20-year-old Xiao Ming; students behind big 2-year-old behind the students behind the back of the students is greater than 2 years old; seek first six students ages

def age(x):
    if x == 0:
        return 20
    x -= 1
    return age(x) + 2
res = age(3)
print(res)

2, Xiao Ming bought a packet of seeds, number of seeds to eat half of the day every day, eat on the 8th day left five found, with recursion he bought a total number of seeds

def sum(x):
    if x == 0:
        return 5
    x -= 1
    return sum(x) * 2
res = sum(8)
print(res)