title: Getting an error in Python when trying to use stdin: io.UnsupportedOperation: fileno
body: <p>I am trying to std in an xml file.  I read the xml file from subversion, updated a line in the file and now I am trying to create a jenkins job by using subporcess.Popen and stdin</p>
  
  <pre><code>test = subprocess.Popen('svn cat http://localhost/svn/WernerTest/JenkinsJobTemplates/trunk/smartTemplate.xml --username admin --password admin', stdout=subprocess.PIPE, universal_newlines=True)
  job = test.stdout.read().replace("@url@", "http://localhost/svn/WernerTest/TMS/branches/test1")
  output = io.StringIO()
  output.write(job)
  subprocess.Popen('java -jar D:\\applications\\Jenkins\\war\\WEB-INF\\jenkins-cli.jar\\jenkins-cli.jar -s http://localhost:8080/ create-job test7', stdin=output)
  </code></pre>
  
  <p>and I am getting the following error:</p>
  
  <pre><code>Traceback (most recent call last):  File "D:\scripts\jenkinsGetJobs.py", line 20, in &lt;module&gt;
  subprocess.Popen('java -jar D:\\applications\\Jenkins\\war\\WEB-INF\\jenkins-cli.jar\\jenkins-cli.jar -s http://localhost:8080/ create-job test7', stdin=output)
  File "D:\applications\Python 3.5\lib\subprocess.py", line 914, 
  in __init__errread, errwrite) = self._get_handles(stdin, stdout, stderr)
  File "D:\applications\Python 3.5\lib\subprocess.py", line 1127, in _get_handles
  p2cread = msvcrt.get_osfhandle(stdin.fileno())
  io.UnsupportedOperation: fileno
  </code></pre>
  
  <p>So how do I pass in the updated file to the next subprocess?</p>