no coding= option fo subprocess.Popen()

[Skaperen]

i need to read the data as it arrives, hence the need for the pipe. it had previously written the data to a temporary file and read the file and that got str from read, but now i need to read from a pipe, and now i get bytes. i will look at another possible design, but i do want to solve this with Popen(). on your ping command test, try doing it without the option -n 4 on the command and get your pings out as they arrive.

---

i just did try run() and it looks like (from the trace dump) that it calls Popen() itself, passing all the keyword options. my documentation does not show an encoding= option for either run() or Popen().

Output:
Traceback (most recent call last):
  File "test1.py", line 10, in <module>
    out = run(['aws','s3','ls'],encoding='utf-8',capture_output=True)
  File "/usr/lib/python3.5/subprocess.py", line 693, in run
    with Popen(*popenargs, **kwargs) as process:
TypeError: __init__() got an unexpected keyword argument 'encoding'

---

from the source code:

Output:
lt2a/forums /home/forums 8> cat -n /usr/lib/python3.5/subprocess.py|lines 830 874
   830	class Popen(object):
   831	
   832	    _child_created = False  # Set here since __del__ checks it
   833	
   834	    def __init__(self, args, bufsize=-1, executable=None,
   835	                 stdin=None, stdout=None, stderr=None,
   836	                 preexec_fn=None, close_fds=_PLATFORM_DEFAULT_CLOSE_FDS,
   837	                 shell=False, cwd=None, env=None, universal_newlines=False,
   838	                 startupinfo=None, creationflags=0,
   839	                 restore_signals=True, start_new_session=False,
   840	                 pass_fds=()):
   841	        """Create new Popen instance."""
   842	        _cleanup()
   843	        # Held while anything is calling waitpid before returncode has been
   844	        # updated to prevent clobbering returncode if wait() or poll() are
   845	        # called from multiple threads at once.  After acquiring the lock,
   846	        # code must re-check self.returncode to see if another thread just
   847	        # finished a waitpid() call.
   848	        self._waitpid_lock = threading.Lock()
   849	
   850	        self._input = None
   851	        self._communication_started = False
   852	        if bufsize is None:
   853	            bufsize = -1  # Restore default
   854	        if not isinstance(bufsize, int):
   855	            raise TypeError("bufsize must be an integer")
   856	
   857	        if _mswindows:
   858	            if preexec_fn is not None:
   859	                raise ValueError("preexec_fn is not supported on Windows "
   860	                                 "platforms")
   861	            any_stdio_set = (stdin is not None or stdout is not None or
   862	                             stderr is not None)
   863	            if close_fds is _PLATFORM_DEFAULT_CLOSE_FDS:
   864	                if any_stdio_set:
   865	                    close_fds = False
   866	                else:
   867	                    close_fds = True
   868	            elif close_fds and any_stdio_set:
   869	                raise ValueError(
   870	                        "close_fds is not supported on Windows platforms"
   871	                        " if you redirect stdin/stdout/stderr")
   872	        else:
   873	            # POSIX
lt2a/forums /home/forums 9>