subprocessでPythonからコマンドを打つときJupyterは使えない

Ubuntu16.04, Python3.6

Pythonからコマンドラインを呼んで、test.pyを実行しようとします(他のプログラムとかでもOK)。これをJupyterでやってしまうとNGです。

import subprocess
import sys

p = subprocess.Popen(["python", "test.py"],
                    stdout=sys.stdout)
p.communicate()

Jupyter(ipython)上で実行するとこういうエラーが出ます。

---------------------------------------------------------------------------
UnsupportedOperation                      Traceback (most recent call last)
 in ()
      3 
      4 p = subprocess.Popen(["python", "test.py"],
----> 5                     stdout=sys.stdout)
      6 p.communicate()

/home/shimo/anaconda3/lib/python3.6/subprocess.py in __init__(self, args, bufsize, executable, stdin, stdout, stderr, preexec_fn, close_fds, shell, cwd, env, universal_newlines, startupinfo, creationflags, restore_signals, start_new_session, pass_fds, encoding, errors)
    665         (p2cread, p2cwrite,
    666          c2pread, c2pwrite,
--> 667          errread, errwrite) = self._get_handles(stdin, stdout, stderr)
    668 
    669         # We wrap OS handles *before* launching the child, otherwise a

/home/shimo/anaconda3/lib/python3.6/subprocess.py in _get_handles(self, stdin, stdout, stderr)
   1182             else:
   1183                 # Assuming file-like object
-> 1184                 c2pwrite = stdout.fileno()
   1185 
   1186             if stderr is None:

/home/shimo/anaconda3/lib/python3.6/site-packages/ipykernel/iostream.py in fileno(self)
    357 
    358     def fileno(self):
--> 359         raise UnsupportedOperation("IOStream has no fileno.")
    360 
    361     def write(self, string):

UnsupportedOperation: IOStream has no fileno.

Jupyterでなく、コマンドラインからPythonを呼ぶとOKです。

# from_commandline.py
import subprocess
import sys

p = subprocess.Popen(["python", "test.py"],
                    stdout=sys.stdout)
p.communicate()

$ python from_commandline.py     

でtest.pyが実行されるはずです。


https://stackoverflow.com/questions/31080829/python-error-io-unsupportedoperation-fileno
https://github.com/ipython/ipykernel/issues/272

参考:Powershellを呼ぶ場合

subprocess.Popen(["powershell.exe", ".....ps1"], stdout=sys.stdout)