os.system question

[kyosohma at gmail.com]

On Dec 28, 1:32 pm, stanleyxu <no_re... at microsoft.com> wrote:
> kyoso... at gmail.com wrote:
> > On Dec 28, 12:57 pm, stanleyxu <no_re... at microsoft.com> wrote:
> >> To note this problem occurs when debugging script in IDLE editor.
> >> When I double click on my_script.py, all outputs will be printed in one
> >> console.
>
> >> --
> >>         ___
> >>    oo  // \\
> >>   (_,\/ \_/ \     Xu, Qian
> >>     \ \_/_\_/>      stanleyxu2005
> >>     /_/   \_\
>
> > Why are you using os.system for these commands in the first place? You
> > should be using the os and shutil modules instead as they would be
> > more cross-platform friendly.
>
> > Something like this:
>
> > # untested
> > for new_folder, old_folder in folder_array:
> >        os.mkdir(new_folder)
> >        shutil.copytree(old_folder, new_folder)
>
> > Adjust the path as needed in the mkdir call.
>
> > See shutil's docs for more info:
> >http://docs.python.org/lib/module-shutil.html
>
> > And here's some folder manipulation docs:
> >http://effbot.org/librarybook/os.htm
>
> > By the by, the subprocess module is supposed to be used in place of
> > the os.system and os.popen* calls:http://docs.python.org/lib/module-subprocess.html
>
> > Mike
>
> Thanks Mike,
>
> you have provided another option.
>
> But my question has not been answered yet. The reason, why I use
> os.system(), is that I want to avoid accident file deletion by writing a
> script. My real script looks like:
>


Technically speaking, the shutil module's copytree function will not
delete ANYTHING if the destination already exists. It will just fail.
You could catch the failed copy with a try/except that prints an
appropriate message detailing the error.

> # 1. Funtion to execute a command in DOS-console
> def execCommand(cmd):
>      if DEBUG_MODE:
>          print 'DOS> ' + cmd;
>      else:
>          os.system(cmd);
>
> # 2.1 Creates temp folder. Removes it first, if it exists.
> if os.path.exists(tmp_folder):
>      execCommand('RD "' + tmp_folder + '" /S /Q');
> execCommand('MD "' + tmp_folder + '"');
>
> # 2.2 Copies all files to the temp folder, that are going to be put in
> package.
> for source_folder, dest_folder in folders_array:
>      if not os.path.exists(dest_folder):
>          execCommand('MD "' + dest_folder + '"');
>      execCommand('XCOPY \"' + source_folder + '" "' + dest_folder + '" /Y');
>
> The benefit is that, when I set DEBUG_MODE=True, I can see what will be
> executed. So that I can make sure that my script will not delete any
> other important files by accident.
>
> --
>         ___
>    oo  // \\
>   (_,\/ \_/ \     Xu, Qian
>     \ \_/_\_/>      stanleyxu2005
>     /_/   \_\


Carl Banks mentioned the subprocess module too and he pointed out its
output redirection capabilities. I recommend checking those out too.
You may be able to do some redirection by changing where stdout and
stderr print to.

Mike