decorate fabric "lcd" with build step, build #, and time elapsed

gistfile1.py

import time
from fabric.api import local, lcd

_step = 1

def format_step(msg1, step, desc, msg2, fillchar=">", cols=80):
    out = "%s %s %d (%s) %s" % (
        fillchar*3,
        msg1,
        step,
        desc,
        msg2,
    )
    return out + " " + fillchar*(cols-len(out))

class step(object):
    def __init__(self, path, desc):
        self.desc = desc
        self.start = 0
        self.path = path
        self.ctxmgr = lcd(path)
    def __enter__(self, *args, **kwargs):
        global _step
        print format_step("START STEP", _step, self.desc, "at dir %r" % self.path)
        self.start = time.time()
        return self.ctxmgr.__enter__(*args, **kwargs)
    def __exit__(self, *args, **kwargs):
        global _step
        ret = self.ctxmgr.__exit__(*args, **kwargs)
        print format_step("FINISH STEP", _step, self.desc, "took %.2fs" % (time.time()-self.start), fillchar="<") + "\n\n"
        _step += 1
        return ret

if __name__ == "__main__":
    with step("ws", "clean workspace & clone"):
        local("pwd && ls")
        time.sleep(0.9)
        local("date")

    with step("ws/something/tests", "run unit tests"):
        local("pwd && ls")
        time.sleep(0.9)
        local("date")

    with step("ws/something", "run pylint"):
        local("pwd && ls")
        time.sleep(0.9)
        local("date")

#output:
"""
$ python ctx_deco.py
>>> START STEP 1 (clean workspace & clone) at dir 'ws' >>>>>>>>>>>>>>>>>>>>>>>>>>
[localhost] local: pwd && ls
/Users/steven/ws
something
[localhost] local: date
Tue Mar  6 18:38:04 PST 2012
<<< FINISH STEP 1 (clean workspace & clone) took 0.91s <<<<<<<<<<<<<<<<<<<<<<<<<<


>>> START STEP 2 (run unit tests) at dir 'ws/something/tests' >>>>>>>>>>>>>>>>>>>
[localhost] local: pwd && ls
/Users/steven/ws/something/tests
[localhost] local: date
Tue Mar  6 18:38:05 PST 2012
<<< FINISH STEP 2 (run unit tests) took 0.91s <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<


>>> START STEP 3 (run pylint) at dir 'ws/something' >>>>>>>>>>>>>>>>>>>>>>>>>>>>>
[localhost] local: pwd && ls
/Users/steven/ws/something
tests
[localhost] local: date
Tue Mar  6 18:38:06 PST 2012
<<< FINISH STEP 3 (run pylint) took 0.91s <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
"""