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我剛開始研究python的管道方法。 我試圖將管道描述符包裝到文件對象中並逐行讀取。無法打開由Python中的線程創建的管道描述符
import os,time,threading
def child():
while True:
time.sleep(1)
msg = ('Spam\n').encode()
os.write(pipeout,msg)
def parent():
while True:
a = os.fdopen(pipein)
line = a.readline()[:-1]
print('Parent %d got [%s] at %s' % (os.getpid(),line,time.time()))
pipein,pipeout = os.pipe()
threading.Thread(target=child,args=()).start()
parent()
當我運行該腳本,結果如下----腳本只是工作在第一次迭代,然後會顯示錯誤消息
Parent 621 got [Spam] at 1376785841.4
Traceback (most recent call last):
File "/Users/miteji/pipe-thread.py", line 43, in <module>
parent()
File "/Users/miteji/pipe-thread.py", line 36, in parent
line = a.readline()[:-1]
IOError: [Errno 9] Bad file descriptor
>>> Exception in thread Thread-1:
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 551, in __bootstrap_inner
self.run()
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 504, in run
self.__target(*self.__args, **self.__kwargs)
File "/Users/miteji/pipe-thread.py", line 30, in child
os.write(pipeout,msg)
OSError: [Errno 32] Broken pipe
然而,當我改變
a = os.fdopen(pipein)
line = a.readline()[:-1]
到
line = os.read(pipein,32)
腳本工作正常。
那麼爲什麼「os.fdopen」方法不能使用?爲什麼管道壞了?謝謝你們!
我明白了!有用!謝謝! – user2301339