Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #17762 > unrolled thread

Re: reading multiline output

Back to article view | Back to comp.lang.python

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: reading multiline output MRAB <python@mrabarnett.plus.com> - 2011-12-23 01:18 +0000

#17762 — Re: reading multiline output

On 23/12/2011 01:07, Mac Smith wrote:
>
> On 23-Dec-2011, at 6:17 AM, MRAB wrote:
>
>> On 23/12/2011 00:33, Mac Smith wrote:
>>> Hi,
>>>
>>>
>>> I have started HandBrakeCLI using subprocess.popen but the output
>>> is multiline and not terminated with \n so i am not able to read
>>> it using readline() while the HandBrakeCLI is running. kindly
>>> suggest some alternative. i have attached the output in a file.
>>>
>> The lines are terminated with \r, so read with read() and then
>> split on "\r".
>
> read() will read the complete output and than i will be able to parse
> it, i want to read the output of the command in realtime.
>
Try telling it how much to read with read(size):

def read_lines(output, line_ending="\n"):
     buffer = ""

     while True:
         chunk = output.read(1024)
         if not chunk:
             break

         buffer += chunk

         while True:
             pos = buffer.find(line_ending)
             if pos < 0:
                 break

             pos += len(line_ending)
             yield buffer[ : pos]
             buffer = buffer[pos : ]

     if buffer:
         yield buffer

[toc] | [standalone]

Back to top | Article view | comp.lang.python

csiph-web