3.生成器的应用

用生成器实现遍历Person类的实例对象：

class Person:
    def __init__(self, name, age, gender, address):
        self.name = name
        self.age = age
        self.gender = gender
        self.address = address
        self.__attr = [name, age, gender, address]

    def __iter__(self):
        # yield self.name
        # yield self.age
        # yield self.gender
        # yield self.address
        yield from self.__attr

p1 = Person('张三', 18, '男', '北京昌平')
# 目标：
for attr in p1:
    print(attr)

用生成器实现斐波那契数列：

def fibo(total):
    pre = 1
    cur = 1

    for index in range(total):
        if index < 2:
            yield 1
        else:
            value = pre + cur
            pre = cur
            cur = value
            yield value

f1 = fibo(10)

for item in f1:
    print(item)

无论是迭代器，还是生成器对象，都可以用list、tuple、set等直接拿到其里面的所有内容（注意：如果数据量很大，可能会挤爆内存）

def fibo(total):
    pre = 1
    cur = 1

    for index in range(total):
        if index < 2:
            yield 1
        else:
            value = pre + cur
            pre = cur
            cur = value
            yield value

f1 = fibo(10)

result = set(f1)
print(result)