64 lines
1.5 KiB
Python
64 lines
1.5 KiB
Python
# encoding: utf-8
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"""
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Topic: sample
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Desc :
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Python生成器：生成器是一个带有yield语句的函数。
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一个生成器能暂停并返回一个中间结果，返回这个值给调用者并暂停执行。
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当生产器的next()方法被调用时，它会准确的从离开的那个地方继续
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"""
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from random import randint
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__author__ = 'Xiong Neng'
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# 生成器函数定义
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def simpleGen():
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yield 1
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yield '2--->punch'
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def gendemo():
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print(simpleGen().__next__())
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print(simpleGen().__next__())
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# 生成器对象的获取
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a = simpleGen()
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print(a.__next__())
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print(a.__next__())
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# Python的for循环有next()调用和对StopIteration的处理
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# 天生就是使用生成器的好手段
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for eachItem in simpleGen():
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print(eachItem)
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# 序列的随机迭代器 pop index out of range ？？？？？？
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def randGen(alist):
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while len(alist) > 0:
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yield alist.pop(randint(0, len(alist)))
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def counter(start_at=0):
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print('new start...%d' % (start_at,))
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count = start_at
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while True:
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val = (yield count)
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print('count=%s, val=%s' % (count, val,))
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if val is not None:
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count = val
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else:
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count += 1
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if __name__ == '__main__':
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count = counter(5)
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print(count.__next__())
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print(count.__next__())
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print(count.__next__())
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print(count.send(99))
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print(count.__next__())
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count.close()
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# print(count.next()) # ERROR
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