python基本语法3.3--迭代器

print(type(range(10)))
# 平方表
square_table = []
for i in range(5000):
    square_table.append(i * i)
for i in range(5):
    print(square_table[i])

square_generator = (x * x for x in range(50000))
print(type(square_generator))
for i in range(5):
    print(next(square_generator))

def fib(limit):
    n ,a, b = 0, 0, 1
    while n < limit:
        yield b
        a, b = b, a + b
        n += 1
    return 'done'


import traceback
f = fib(5)
print('*********')
print(type(f))
print(next(f))
print(next(f))
print(next(f))
print(next(f))
print(next(f))

try:
    print(next(f))
except StopIteration:
    traceback.print_exc()

print('***')
for i in fib(5):
    print(i)