python recipe

importer

import os
import imp

WORKDIR = os.path.dirname(os.path.abspath(__file__))
path = lambda *a: os.path.join(WORKDIR, *a)
importer = lambda m, path: imp.load_module(m, *imp.find_module(m, [path]))

rec generator

def parseMetrics(data, conf):
    if type(data) == type(conf):
        if isinstance(conf, dict):
            for k, v in conf.iteritems():
                if isinstance(v, tuple):
                    yield v, data[k]
                else:
                    for y in parseMetrics(data[k], conf[k]): yield y
        elif isinstance(conf, list):
            for i in conf:
                for y in parseMetrics(_getFromList(data, i), i): yield y
    else:
        #raise Exception("parseMetrics conf and data type error")
        pass

safe_popen

import sys, os
import subprocess

def safe_popen(cmd, stdin=None, stdout=None):
    """
    Safe way to execute subprocess.Popen:
        subprocess.Popen(extractcmd, shell = True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, executable="/bin/bash")
    Args:
        cmd: cmd to execute
        stdin: standard input, don't pass subprocess.PIPE
        stdout: standard output, don't pass subprocess.PIPE
    Returns:
        tuple(returncode, stderr)
    """
    p = subprocess.Popen(cmd, shell = True, stdin=stdin, stdout=stdout, stderr=subprocess.PIPE, executable="/bin/bash")
    err_list = []
    while True:
        next_line = p.stderr.readline()
        err_list.append(next_line)
        if next_line == '' and p.poll() != None:
            break
    return p.returncode, ''.join(err_list)

def bad_popen(cmd, stdin=None, stdout=None):
    p = subprocess.Popen(cmd, shell = True, stdin=stdin, stdout=stdout, stderr=subprocess.PIPE, executable="/bin/bash")
    p.wait()
    return p.returncode, p.stderr.read()

if __name__ == "__main__":
    #http://www.commandlinefu.com/commands/view/7949/generate-random-password-works-on-mac-os-x
    returncode, err = safe_popen("ls -al a")
    print "returncode = ", returncode, " err = ", err
    returncode, err = safe_popen("openssl rand -base64 70000 >&2")
    print "returncode = ", returncode, " len(err) = ", len(err)
    returncode, err = bad_popen("ls -al a")
    print "returncode = ", returncode, " err = ", err
    returncode, err = bad_popen("openssl rand -base64 70000 >&2")
    print "returncode = ", returncode, " len(err) = ", len(err)

subprocess_parent_exit

#coding=utf8

from subprocess import Popen
popen = Popen(["ping", "google.com"])
from time import sleep
sleep(100)