Re: bash/shell to python
FWIW, I do manual argument parsing, because pylint understands how to detect typos with manual argument parsing, but not the highly dynamic modules that parse arguments. On Wed, May 16, 2012 at 7:16 PM, Rita rmorgan...@gmail.com wrote: Hello, I currently build a lot of interfaces/wrappers to other applications using bash/shell. One short coming for it is it lacks a good method to handle arguments so I switched to python a while ago to use 'argparse' module. Its a great complement to subprocess module. I was wondering if there is a generic framework people follow to build python scripts which are replacing shell scripts? Is there a guide or a template to follow? -- --- Get your facts first, then you can distort them as you please.-- -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: bash/shell to python
On 19May2012 08:27, Michael Torrie torr...@gmail.com wrote:
| On 05/16/2012 08:16 PM, Rita wrote:
| I currently build a lot of interfaces/wrappers to other applications
| using bash/shell. One short coming for it is it lacks a good method
| to handle arguments so I switched to python a while ago to use
| 'argparse' module.
|
| Actually there is a great way of parsing command line options in
| bash, using the GNU getopt program. See:
| http://www.manpagez.com/man/1/getopt/
|
| This command is available on all Linux systems, and most BSD systems.
| There's also freegetopt, a BSD implementation for unix, MSDOS, or Windows.
And if you don't want to do option bundling it's easy enough to write a
simple option parser without getopt at all.
My standard option parsing looks somewhat like this:
# some things to control via the options
the_file=
doit=1
trace=
# badness?
badopts=
while [ $# -gt 0 ]
do
case $1 in
-f) the_file=$2; shift ;;
-n) doit= ;;
-x) trace=1 ;;
--) shift; break ;;
-?*) echo $0: unrecognised option: $1 2
badopts=1
;;
*)break ;;
esac
shift
done
# ... parse non-option arguments ...
[ $badopts ] { echo $usage 2; exit 2; }
# ... rest of program ...
There's nothing hard there.
Cheers,
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http://www.cskk.ezoshosting.com/cs/
Any profit should go to Arnie's `get the daemon carved on Mount Rushmore' fund.
- Marty Albini, DOD0550, mar...@sdd.hp.com
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Re: bash/shell to python
On 05/16/2012 08:16 PM, Rita wrote: I currently build a lot of interfaces/wrappers to other applications using bash/shell. One short coming for it is it lacks a good method to handle arguments so I switched to python a while ago to use 'argparse' module. Actually there is a great way of parsing command line options in bash, using the GNU getopt program. See: http://www.manpagez.com/man/1/getopt/ This command is available on all Linux systems, and most BSD systems. There's also freegetopt, a BSD implementation for unix, MSDOS, or Windows. Its a great complement to subprocess module. I was wondering if there is a generic framework people follow to build python scripts which are replacing shell scripts? Is there a guide or a template to follow? Besides the advice given by the other posters in this thread, here is a very good document on some unique aspects of python that are well suited to doing system programming or shell scripting in python: http://www.dabeaz.com/generators/ This describes how generators can be used to replace pipes with something that is quite efficient and very pythonic. See the presentation pdf first. -- http://mail.python.org/mailman/listinfo/python-list
Re: bash/shell to python
On Thu, May 17, 2012 at 12:16 PM, Rita rmorgan...@gmail.com wrote: Hello, I currently build a lot of interfaces/wrappers to other applications using bash/shell. One short coming for it is it lacks a good method to handle arguments so I switched to python a while ago to use 'argparse' module. Its a great complement to subprocess module. I was wondering if there is a generic framework people follow to build python scripts which are replacing shell scripts? Is there a guide or a template to follow? It's generally accepted that it's easier to port a shell than a shell script. That said, though, Python does have some good shell-like functionality - look at the shutil module (along with subprocess which you've already seen). To create optimal Python code, though, you're going to have to look through the shell script, understand what it's actually doing, and rewrite that logic in Python. chrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: bash/shell to python
On Wed, May 16, 2012 at 7:16 PM, Rita rmorgan...@gmail.com wrote: Hello, I currently build a lot of interfaces/wrappers to other applications using bash/shell. One short coming for it is it lacks a good method to handle arguments so I switched to python a while ago to use 'argparse' module. Its a great complement to subprocess module. I was wondering if there is a generic framework people follow to build python scripts which are replacing shell scripts? Is there a guide or a template to follow? Not really. The new Plumbum library looks pretty awesome though: http://plumbum.readthedocs.org/en/latest/index.html There are also a few 3rd-party wrapper libraries for the `subprocess` module available to make using it more convenient (e.g. `envoy`). Cheers, Chris -- http://mail.python.org/mailman/listinfo/python-list
bash/shell to python
Hello, I currently build a lot of interfaces/wrappers to other applications using bash/shell. One short coming for it is it lacks a good method to handle arguments so I switched to python a while ago to use 'argparse' module. Its a great complement to subprocess module. I was wondering if there is a generic framework people follow to build python scripts which are replacing shell scripts? Is there a guide or a template to follow? -- --- Get your facts first, then you can distort them as you please.-- -- http://mail.python.org/mailman/listinfo/python-list
Re: Bash shell to Python shell?
Chris Rebert c...@rebertia.com wrote: On Sun, Sep 27, 2009 at 8:13 PM, edwithad edwit...@hotmail.com wrote: I am sure you have not read a question this basic in some time, but I am curious. Using Linux I open a terminal window and type: python. Does Bash Shell go away and to become a Python Shell, or is it still a Bash Shell with Python running inside? Thanks in advance. The latter. Press Ctrl+D or enter exit() or quit() to exit Python and return to bash. Or, if you prefer the bash shell to be replaced with the python, just type: exec python -- --- | Radovan Garabík http://kassiopeia.juls.savba.sk/~garabik/ | | __..--^^^--..__garabik @ kassiopeia.juls.savba.sk | --- Antivirus alert: file .signature infected by signature virus. Hi! I'm a signature virus! Copy me into your signature file to help me spread! -- http://mail.python.org/mailman/listinfo/python-list
Bash shell to Python shell?
I am sure you have not read a question this basic in some time, but I am curious. Using Linux I open a terminal window and type: python. Does Bash Shell go away and to become a Python Shell, or is it still a Bash Shell with Python running inside? Thanks in advance. -- http://mail.python.org/mailman/listinfo/python-list
Re: Bash shell to Python shell?
On Sun, Sep 27, 2009 at 8:13 PM, edwithad edwit...@hotmail.com wrote: I am sure you have not read a question this basic in some time, but I am curious. Using Linux I open a terminal window and type: python. Does Bash Shell go away and to become a Python Shell, or is it still a Bash Shell with Python running inside? Thanks in advance. The latter. Press Ctrl+D or enter exit() or quit() to exit Python and return to bash. Cheers, Chris -- http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Bash shell to Python shell?
In article 2009092721134550073-edwit...@hotmailcom,
edwithad edwit...@hotmail.com wrote:
I am sure you have not read a question this basic in some time, but I
am curious. Using Linux I open a terminal window and type: python.
Does Bash Shell go away and to become a Python Shell, or is it still a
Bash Shell with Python running inside? Thanks in advance.
See for youself:
$ ps
PID TTY TIME CMD
17478 pts/000:00:00 bash
17571 pts/000:00:00 ps
$ python
Python 2.5.4 (r254:67916, Feb 17 2009, 20:16:45)
[GCC 4.3.3] on linux2
Type help, copyright, credits or license for more information.
import os
os.system('ps')
PID TTY TIME CMD
17478 pts/000:00:00 bash
17572 pts/000:00:00 python
17573 pts/000:00:00 sh
17574 pts/000:00:00 ps
0
So you can see that the top-level shell (process id 17478) starts new
child processes to run other programs (17571 for the ps in the first
example, 17572 for python in the second), just as the python os.system
function starts a new shell (17573, a default /bin/sh) to process the
'ps' argument string passed to it and that shell starts another process
(17574) to run 'ps'.
For a more detailed explanation of what's going on, see, for example:
http://tldp.org/HOWTO/Unix-and-Internet-Fundamentals-HOWTO/running-progra
ms.html
--
Ned Deily,
n...@acm.org
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Re: Bash shell to Python shell?
On 2009-09-28, Chris Rebert c...@rebertia.com wrote: On Sun, Sep 27, 2009 at 8:13 PM, edwithad edwit...@hotmail.com wrote: I am sure you have not read a question this basic in some time, but I am curious. Using Linux I open a terminal window and type: python. Does Bash Shell go away and to become a Python Shell, or is it still a Bash Shell with Python running inside? Thanks in advance. The latter. Press Ctrl+D or enter exit() or quit() to exit Python and return to bash. Bash doesn't really go away. It's still there, it just hands over the terminal to the python interpreter and then sits and waits for the python interpreter to exit. At that point the Bash shell (the same one as before) resumes. -- Grant -- http://mail.python.org/mailman/listinfo/python-list
