Jul-24-2018, 08:22 PM
HI, I am a newbie of python and tried to use mixed python and shell code in my python script to achieve my goal. Therefore I use quite a lot of os.system() and/or subprocess.call(). I found that for some commands, the python generate different output from run shell directly. For example:
I have a source text file sample.txt which has lines ended with ":". I'd like to combine this kind of line with the next line. Since I know how to do this easily using vim, like "vim -e -c '%s/:\n/:/' -c 'wq' sample.txt", in my python code, I tried to os.system("vim -e -c '%s/:\n/:/' -c 'wq' sample.txt"), but the substitution did not happen. It looks like the "\n" is not recognized (it works when '%s/:/:ABC/'). Same behavior for subprocess.call("vim -e -c '%s/:\n/:/' -c 'wq' sample.txt", shell=True).
So my question: is os.system(shell_cmd) supposed to generate same result as running the shell_cmd directly? Any way to get around the above problem, yet still use vim instead of new python code?
My environment: python 2.7, bash under linux.
Thanks.
--Karl
I have a source text file sample.txt which has lines ended with ":". I'd like to combine this kind of line with the next line. Since I know how to do this easily using vim, like "vim -e -c '%s/:\n/:/' -c 'wq' sample.txt", in my python code, I tried to os.system("vim -e -c '%s/:\n/:/' -c 'wq' sample.txt"), but the substitution did not happen. It looks like the "\n" is not recognized (it works when '%s/:/:ABC/'). Same behavior for subprocess.call("vim -e -c '%s/:\n/:/' -c 'wq' sample.txt", shell=True).
So my question: is os.system(shell_cmd) supposed to generate same result as running the shell_cmd directly? Any way to get around the above problem, yet still use vim instead of new python code?
My environment: python 2.7, bash under linux.
Thanks.
--Karl
