#python 3.5 ， win10
引入包
#os.chdir(‘path‘)
import os
import subprocess
#https://docs.python.org/3.5/library/subprocess.html?highlight=subprocess#module-subprocess
#http://ltp.readthedocs.io/zh_CN/latest/ltptest.html
Run 1 process
p1 = subprocess.Popen(‘cws_cmdline --input input_file.txt ‘,stdout=subprocess.PIPE,stderr=subprocess.PIPE [,universal_newlines=True])
#p1 = subprocess.Popen([‘cws_cmdline‘,‘--input‘, ‘input_file.txt ‘],stdout=subprocess.PIPE,stderr=subprocess.PIPE)
#universal_newlinews 为 True 时，输入为 str 流，(默认)为 False 时为 byte 流
output_10 = p1.communicate()[0] #stdin
output_11 = p1.communicate()[1] #stderr
Run pipe-line
p1 = subprocess.Popen(‘cws_cmdline --input input_file.txt ‘,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
p2 = subprocess.Popen(‘pos_cmdline --input no_file.txt ‘,stdin=p1.stdout,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
p3 = subprocess.Popen(‘ner_cmdline --input no_file.txt ‘,stdin=p2.stdout,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
#if call p1|2.communicate()[0|1] before p3.communicate(), pipeline will break at p1|p2, because the before stdout|stderr pipe will be extract and not use anymore
#if call p1|2.communicate()[0|1] before p3 = constructor, will get ValueError: I/O operation on closed file
output30 = p3.communicate()[0] #stdout
output31 = p3.communicate()[1] #stderr
#if call p1|2.communicate()[0|1] after p3.communicate(), will get close warning.
‘‘‘ def communicate(self, input=None, timeout=None):
#...
if self.stdin:
self._stdin_write(input)
elif self.stdout:
stdout = self.stdout.read()
self.stdout.close()
elif self.stderr:
stderr = self.stderr.read()
self.stderr.close()
self.wait()
#...
‘‘‘
Run process one by one
#px.communicate() actually run the pipe line until px, all the pipe content(p1&p2&p3.stdin&stdout&stderr pipe) will be extract and not usable any more .
#if you want to save each pipe line node‘s meadian content , you need to use a new pipe as stdin=subprocess.PIPE , and use communicate(‘input Popen‘s stdin content‘)
p1 = subprocess.Popen(‘cws_cmdline --input input_file.txt ‘,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
output_10 = p1.communicate()[0]
output_11 = p1.communicate()[1]
str_10 = output_10.decode(‘utf-8‘)
str_11 = output_10.decode(‘utf-8‘)
p2 = subprocess.Popen(‘pos_cmdline --input no_file.txt ‘,stdin=subprocess.PIPE,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
#communicate(‘input Popen‘s stdin content once if and only if stdin==subprocess.PIPE‘)
output_20 = p2.communicate( bytes(str_10, encoding = ‘utf-8‘) )[0]
output_21 = p2.communicate()[1]
# for px.communicate(), only the first time call can you set the input
#or use "universal_newlines=True" for Popen() to process str stream
p3 = subprocess.Popen(‘ner_cmdline --input no_file.txt ‘,stdin=subprocess.PIPE,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
output_3 = p3.communicate( output20)
[output_30, output_31] = output_3