Path: csiph.com!news.swapon.de!fu-berlin.de!uni-berlin.de!not-for-mail From: Tim Johnson Newsgroups: comp.lang.python Subject: Using subprocess to capture a progress line Date: Tue, 10 Nov 2015 13:47:56 -0900 Organization: AkWebsoft Lines: 55 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: news.uni-berlin.de m9Q3vnbGltskGyaTAtU46AmhuWhfW5Wts0YEBUoPrCug== Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.009 X-Spam-Evidence: '*H*': 0.98; '*S*': 0.00; 'bash': 0.07; 'finished.': 0.07; 'line:': 0.07; 'newline': 0.07; 'tmp': 0.07; '###': 0.09; 'python': 0.10; 'output': 0.13; 'carriage': 0.16; 'collins': 0.16; 'manifest': 0.16; 'received:io': 0.16; 'received:psf.io': 0.16; 'subprocess': 0.16; 'true:': 0.16; 'uses,': 0.16; 'app': 0.16; 'runs': 0.18; "aren't": 0.22; 'player': 0.23; 'tim': 0.24; 'written': 0.24; "i've": 0.25; 'header:User-Agent:1': 0.26; 'command': 0.26; 'question': 0.27; 'executing': 0.27; 'function': 0.28; 'command-line': 0.29; 'container': 0.29; 'follows': 0.29; 'print': 0.30; 'code': 0.30; 'run': 0.33; 'clarify': 0.33; 'downloading': 0.33; 'ubuntu': 0.33; "i'll": 0.33; 'file': 0.34; 'running': 0.34; 'info': 0.34; 'i.e.': 0.35; 'but': 0.36; 'there': 0.36; 'lines': 0.36; 'to:addr:python-list': 0.36; 'being': 0.37; 'method': 0.37; 'thanks': 0.37; 'charset:us-ascii': 0.37; 'progress': 0.38; 'reports': 0.38; 'does': 0.39; 'application': 0.39; 'skip:- 60': 0.39; 'to:addr:python.org': 0.40; 'show': 0.62; 'video': 0.62; 'information': 0.63; 'times': 0.63; 'soon': 0.65; 'numerous': 0.66; 'webpage': 0.66; '100%': 0.72; 'correcting': 0.84; 'subject:Using': 0.84; 'fyi': 0.91; 'judy': 0.91 Mail-Followup-To: Python ML Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.20+ Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Xref: csiph.com comp.lang.python:98618 Using python 2.7.6 on ubuntu 14.04 The application in question is run with bash and gnome-terminal : I've written a command-line "wrapper" for youtube-dl, executing youtube-dl as a subprocess. ------------------------------------------------------------------ youtube-dl reports download progress on one line. I.E. the line is overwritten numerous times with no carriage return until the downloading is finished. ------------------------------------------------------------------ The following code runs the youtube-dl command and reports each line as output by youtube-dl ########### p = subprocess.Popen(list(args), stderr=subprocess.STDOUT, stdout=subprocess.PIPE) while True: line = p.stdout.readline() if not line: break tmp = line.strip() print tmp ########### However this method not does show the download progress _until_ the download is complete. To clarify : follows is output from my app running youtube-dl. I've annotated the line in question with '###' [youtube] ZIgnHPqp0Dk: Downloading webpage [youtube] ZIgnHPqp0Dk: Downloading video info webpage [youtube] ZIgnHPqp0Dk: Extracting video information [youtube] ZIgnHPqp0Dk: Downloading js player en_US-vfljDEtYP [youtube] ZIgnHPqp0Dk: Downloading DASH manifest [download] Destination: Someday Soon - Judy Collins 1969.avi.m4a ### the line below is not seen until download is finished. [download] 100% of 7.58MiB in 00:12.85KiB/s ETA 00:00 [ffmpeg] Correcting container in "Someday Soon - Judy Collins 1969.avi.m4a" [ffmpeg] Destination: Someday Soon - Judy Collins 1969.avi.mp3 Deleting original file Someday Soon - Judy Collins 1969.avi.m4a (pass -k to keep) Is there a way to code subprocess so the the progress is being shown? In my case lines being output aren't being shown unless a newline is sent, or so I understand it. FYI : the need for this function in this case is trivial, but the solution will be enlightening for me and have other uses, I'll bet. thanks -- Tim http://www.akwebsoft.com, http://www.tj49.com