4 ms·

Plumbum: Pythonic Shell Combinators

76 points by mnazim 14y ago

mariocesar 14y ago
The coolest thing I see this year!
friggeri 14y ago
Someone needs to explain to me in what parallel universe (sudo[ifconfig["-a"]] | grep["-i", "loop"]) & FG is more readable than sudo ifconfig -a | grep -i loop &
- tav 14y ago
  It's not. The reasons that one might use `plumbum` are similar to the reasons that one might use `fabric` instead of just running local/remote shell scripts, i.e. - Ability to leverage the richness of Python to pre/post-process the inputs/outputs from other shell commands. - Easier to parameterise and maintain. - Familiarity with Python over the likes of bash, zsh, etc.
  - gbog 14y ago
    Em, the fabric version would be much more readable I'm not mistaken: local("ls - l | grep foo")
    - jshharlow 14y ago
      From looking at the code it seems like plumbum is more object oriented, instead of having stuff like https://github.com/fabric/fabric/blob/master/fabric/state.py#L267 https://github.com/fabric/fabric/blob/master/fabric/state.py... in fabric, so thats a good move forward.
      - cheatercheater 14y ago
        Yes, because OOP is salvation. Right?
        harlowja 14y ago
        Right, lol.
- sirclueless 14y ago
  It's definitely not, until you need to access the stdout of that command programmatically. Plumbum replaces the subprocess module (and os.system etc.), not shell scripts, despite their motto. It might displace shell scripts, because once you can use lists, maps, functions with actual arguments, etc. why would you go back? But it's not going to replace shell one-liners any time soon.
- tomerfiliba 14y ago
  you probably didn't want the "& FG" part, as it would go to the screen and run "in the foreground", e.g., make you wait. but anyway, as other people have said, it aims at providing an object oriented replacement for shell scripts, etc.
  - seliopou 14y ago
    This is not an object-oriented replacement for shell scripts. This is a shell script DSL embedded in Python. If you want to use Python to manipulate the input or output of shell commands, then write a Python script that reads from stdin and writes to stdout, and use the shell to insert that script into the appropriate point in your command chain. It's the UNIX way.
jal278 14y ago
This reminds me of when I first saw drop-box: Immediate recognition of the pain it will save me. I often hack up kludges that approximate this -- os.system calls that pipe to a file, then I read and parse the file. Good work.
- robrenaud 14y ago
  The commands module is now deprecated by the overly complicated subprocess module, but content = commands.getoutput(x) is much better than os.system(x + ' > foo') content = open('foo', 'r').read()
  - icebraining 14y ago
    The subprocess mode is really not that complicated. Your example can be written as: content = subprocess.check_output(x, shell=True)
colinmarc 14y ago
Some really clever tricks here. I particularly like the __getitem__ one. I'm simultaneously excited and filled with horror. =)
gbog 14y ago
I think this attempt and other simile are fun but I doubt I would use them for serious things. Maybe it should be done the other way: like markdown is an extension of html, we could have an extension of shell with python syntax.
tveita 14y ago
I'm sure it's convenient, but I wouldn't call this kind of operator overloading "pythonic". Not to say being pythonic is always better, but some of these tricks don't even seem that practical. Why "& FG" instead of .fg()? Using division for joining paths is cute, but why not use '+', the conventional append operator?
- tomerfiliba 14y ago
  &FG and &BG are just shell-ish shortcuts. you can always use .popen() or .run()
ehosca 14y ago
thats Lead ....
cing 14y ago
While we're on the topic, here's another shell scripting package for Python: https://github.com/amoffat/pbs https://github.com/amoffat/pbs
- tomerfiliba 14y ago
  see http://readthedocs.org/docs/plumbum/en/latest/#credits http://readthedocs.org/docs/plumbum/en/latest/#credits
cheatercheater 14y ago
Haskell has done it long ago and much better: http://news.ycombinator.com/item?id=3966630 http://news.ycombinator.com/item?id=3966630
jhales 14y ago
I'm not quite sure I understand the value added over "!ls" etc on iPython. Is this module primarily for use on the vanilla interpreter?

76 points by mnazim 14y ago

The coolest thing I see this year!

Someone needs to explain to me in what parallel universe (sudo[ifconfig["-a"]] | grep["-i", "loop"]) & FG is more readable than sudo ifconfig -a | grep -i loop &

tav 14y ago
It's not. The reasons that one might use `plumbum` are similar to the reasons that one might use `fabric` instead of just running local/remote shell scripts, i.e. - Ability to leverage the richness of Python to pre/post-process the inputs/outputs from other shell commands. - Easier to parameterise and maintain. - Familiarity with Python over the likes of bash, zsh, etc.
- gbog 14y ago
  Em, the fabric version would be much more readable I'm not mistaken: local("ls - l | grep foo")
  - jshharlow 14y ago
    From looking at the code it seems like plumbum is more object oriented, instead of having stuff like https://github.com/fabric/fabric/blob/master/fabric/state.py#L267 https://github.com/fabric/fabric/blob/master/fabric/state.py... in fabric, so thats a good move forward.
    - cheatercheater 14y ago
      Yes, because OOP is salvation. Right?
      - harlowja 14y ago
        Right, lol.
sirclueless 14y ago
It's definitely not, until you need to access the stdout of that command programmatically. Plumbum replaces the subprocess module (and os.system etc.), not shell scripts, despite their motto. It might displace shell scripts, because once you can use lists, maps, functions with actual arguments, etc. why would you go back? But it's not going to replace shell one-liners any time soon.
tomerfiliba 14y ago
you probably didn't want the "& FG" part, as it would go to the screen and run "in the foreground", e.g., make you wait. but anyway, as other people have said, it aims at providing an object oriented replacement for shell scripts, etc.
- seliopou 14y ago
  This is not an object-oriented replacement for shell scripts. This is a shell script DSL embedded in Python. If you want to use Python to manipulate the input or output of shell commands, then write a Python script that reads from stdin and writes to stdout, and use the shell to insert that script into the appropriate point in your command chain. It's the UNIX way.

jal278 14y ago

This reminds me of when I first saw drop-box: Immediate recognition of the pain it will save me. I often hack up kludges that approximate this -- os.system calls that pipe to a file, then I read and parse the file. Good work.

robrenaud 14y ago
The commands module is now deprecated by the overly complicated subprocess module, but content = commands.getoutput(x) is much better than os.system(x + ' > foo') content = open('foo', 'r').read()
- icebraining 14y ago
  The subprocess mode is really not that complicated. Your example can be written as: content = subprocess.check_output(x, shell=True)

colinmarc 14y ago

Some really clever tricks here. I particularly like the __getitem__ one. I'm simultaneously excited and filled with horror. =)

gbog 14y ago

I think this attempt and other simile are fun but I doubt I would use them for serious things. Maybe it should be done the other way: like markdown is an extension of html, we could have an extension of shell with python syntax.

tveita 14y ago

I'm sure it's convenient, but I wouldn't call this kind of operator overloading "pythonic". Not to say being pythonic is always better, but some of these tricks don't even seem that practical. Why "& FG" instead of .fg()? Using division for joining paths is cute, but why not use '+', the conventional append operator?

tomerfiliba 14y ago
&FG and &BG are just shell-ish shortcuts. you can always use .popen() or .run()

ehosca 14y ago

thats Lead ....

cing 14y ago

While we're on the topic, here's another shell scripting package for Python: https://github.com/amoffat/pbs https://github.com/amoffat/pbs

tomerfiliba 14y ago
see http://readthedocs.org/docs/plumbum/en/latest/#credits http://readthedocs.org/docs/plumbum/en/latest/#credits

cheatercheater 14y ago

Haskell has done it long ago and much better: http://news.ycombinator.com/item?id=3966630 http://news.ycombinator.com/item?id=3966630

jhales 14y ago

I'm not quite sure I understand the value added over "!ls" etc on iPython. Is this module primarily for use on the vanilla interpreter?