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Why is subprocess.call command not working? - Printable Version

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Why is subprocess.call command not working? - zBernie - Nov-19-2018

In the code snippet below, the subprocess.call command generates the file not found error shown below. However, passing the same variable "command" to os.system works. I've read that subprocess is preferroed over os.system, so I'd like to get that working.

-Thanks


for file in jpgfiles:
    jpgfile = '"' + jpgdir + file + '"'
      
    command = "convert " + str(jpgfile) + " -font Helvetica -pointsize 60 -fill lightblue -quality 100 -gravity southeast -auto-orient -annota
  
    # Generates file not found error shown below
    # subprocess.call([command])

    # WORKS
    os.system(command)
Error:
FileNotFoundError: [Errno 2] No such file or directory: 'convert "/home/bfbarton/CentOS Share/pics/Trenton Makes Bridge-10062018.jpg" -font Helvetica -pointsize 60 -fill lightblue -quality 100 -gravity southeast -auto-orient -annotate +80+50 %[exif:DateTimeOriginal] "/home/bfbarton/CentOS Share/pics/Trenton Makes Bridge-10062018.jpg"': 'convert "/home/bfbarton/CentOS Share/pics/Trenton Makes Bridge-10062018.jpg" -font Helvetica -pointsize 60 -fill lightblue -quality 100 -gravity southeast -auto-orient -annotate +80+50 %[exif:DateTimeOriginal] "/home/bfbarton/CentOS Share/pics/Trenton Makes Bridge-10062018.jpg"'


RE: Why is subprocess.call command not working? - nilamo - Nov-19-2018

For subprocess.call, the first argument is the command you're calling, with args in subsequent elements. In this case, the first element should only be "convert". Args are then passed to it, and will be escaped/quoted as needed for you.

From the docs:
>>> import subprocess
>>> help(subprocess.call)
Help on function call in module subprocess:

call(*popenargs, timeout=None, **kwargs)
    Run command with arguments.  Wait for command to complete or
    timeout, then return the returncode attribute.

    The arguments are the same as for the Popen constructor.  Example:

    retcode = call(["ls", "-l"])

>>>


RE: Why is subprocess.call command not working? - wavic - Nov-19-2018

Line 4, 3 quotes.
You have to break the command by spaces.

command = "convert " + str(jpgfile) + " -font Helvetica -pointsize 60 -fill lightblue -quality 100 -gravity southeast -auto-orient -annota"
command = command.split()


RE: Why is subprocess.call command not working? - zBernie - Nov-19-2018

(Nov-19-2018, 09:02 PM)wavic Wrote: Line 4, 3 quotes.
You have to break the command by spaces.

command = "convert " + str(jpgfile) + " -font Helvetica -pointsize 60 -fill lightblue -quality 100 -gravity southeast -auto-orient -annota"
command = command.split()


Now I'm getting the error below.

-Thanks

jpgdir = "/home/bernie/CentOS Share/pics/"
jpgfiles = fnmatch.filter(os.listdir(jpgdir), '*.jpg')

command = "convert " + str(jpgfile) + " -font Helvetica -pointsize 60 -fill lightblue -quality 100 -gravity southeast -auto-orient -annotate +80+50 %[exif:DateTimeOriginal] " + str(jpgfile)
    command = command.split()

    subprocess.call([command])
Error:
Traceback (most recent call last):
  File "./im-datestamp.py", line 36, in <module>
    subprocess.call([command])
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/subprocess.py", line 267, in call
    with Popen(*popenargs, **kwargs) as p:
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/subprocess.py", line 709, in __init__
    restore_signals, start_new_session)
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/subprocess.py", line 1258, in _execute_child
    executable = os.fsencode(executable)
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/os.py", line 800, in fsencode
    filename = fspath(filename)  # Does type-checking of `filename`.
TypeError: expected str, bytes or os.PathLike object, not list


RE: Why is subprocess.call command not working? - wavic - Nov-19-2018

command is already a list.
Why do you put it in square brackets?

Fix the indentation.

RE: Why is subprocess.call command not working? - snippsat - Nov-19-2018

@zBernie as posted over is best to past in a list,can try with string first then need shell=True.
Can make a list later,as you use 3.6 i have put in some updates.
import subprocess
import os

jpgdir = "/home/bernie/CentOS Share/pics/"
file = 'test.jpg'
jpgfile = os.path.join(jpgdir, file)
command = f'convert "{jpgfile}" -font Helvetica -pointsize 60 -fill lightblue -quality 100 -gravity southeast -auto-orient -annotate +80+50 %[exif:DateTimeOriginal] {jpgfile}'
subprocess.run(command, shell=True)
Dos not work post your original convert command before you take into Python.