os.system调用python失败后继续脚本

Question

我编写了一个脚本来扫描文本文件的目录，如果找到它们，它会创建一个系统调用来在 txt 文件上运行脚本。我仍在处理一些导致我的一些系统调用失败的小错误。但是，我希望这不会杀死我的脚本。我只想知道错误然后继续我的生活。似乎任何成功的调用都返回 0，而任何导致错误的调用都返回 n。我试图将结果与 0 进行比较，但它永远不会那么远。关于我如何做到这一点的任何建议？

import sys, getopt, os

def main(argv):

    def scan_dir(path):
            temp_path = path
            print temp_path
            for file in os.listdir(path):
                    temp_path += file
                    if file.endswith(".txt"):
                            result = os.system("python callscript.py -i %s" % path)
                            if result != 0
                                    print "Error!"

                    temp_path = path


    def usage():
            print "usage:  dostuff.py [hi:]\n \
                  \t -h\t print usage\n \
                  \t -i\t directory path\n"
            sys.exit(2)

    if(len(argv) == 0):
            usage()

    path = ''

    try:
            opts, args = getopt.getopt(argv,"hi:",["path="])
    except getopt.GetoptError:
            usage()

    for opt, arg in opts:
            if opt == '-h':
                    usage()

            elif opt in ("-i", "--ipath"):
                    path = arg
    if path.endswith('/') == False:
            path += '/'

    scan_dir(path)



if __name__ == "__main__":
main(sys.argv[1:])

Answer 1

您应该使用子进程模块，尤其是 check_call，捕获一个 CalledProcessError，对于任何非零退出状态都会引发该模块：

 from subprocess import check_call,CalledProcessError      

  try:
       check_call(["python", "callscript.py", "-i",path])
  except CalledProcessError as e:
       print e.message

遵循您的代码并不容易，我建议不要将所有其他函数嵌套在 main 中。我也会使用glob 来查找txt 文件：

from glob import  glob

def scan_dir(path):
    files = (os.path.join(path,f) for f in glob(os.path.join(path,"*.txt")))
    for fle in files:    
        try:
            check_call(["python", "callscript.py", "-i", fle])
        except CalledProcessError as e:
            print e.message

def usage():
    print "usage:  dostuff.py [hi:]\n \
          \t -h\t print usage\n \
          \t -i\t directory path\n"
    sys.exit(2)


if __name__ == "__main__":
    args = sys.argv[1:]
    if not args:
        usage()
    path = ''
    try:
        opts, args = getopt.getopt(args, "hi:",["path="])
    except getopt.GetoptError:
            usage()

    for opt, arg in opts:
        if opt == '-h':
                usage()
        elif opt in ("-i", "--ipath"):
                    path = arg
    if not path.endswith('/'):
            path += '/'
    scan_dir(path)

Answer 2

1. 如果您要调用 Python 脚本，则应考虑将其集成到您自己的 Python 程序中。
2. 否则，您应该使用 subprocess 模块，这是在 python 文档中推荐的，如os.system 所示。该文档还建议以这种方式编写替换substitute for os.system。请参阅第 17.1.4.3 节。了解如何捕获异常。

Answer 3

要在不停止主进程的情况下捕获错误和输出，我建议使用 subprocess 模块。

import subprocess

processToRun = "python callscript.py -i %s" % path
proc = subprocess.Popen (processToRun, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
print(proc.returncode)

Answer 4

我目前的解决方案：

import sys, getopt, os    
from subprocess import check_call, CalledProcessError


def scan_dir(path):

    fail_count = 0
    success = []
    failure = []

    temp_path = path
    print temp_path
    for file in os.listdir(path):
            temp_path += file
            if file.endswith(".txt"):
                    try:
                            check_call(["python", "callscript.py","-i", temp_path])
                            success.append(file)
                    except CalledProcessError as e:
                            print e.message
                            failure.append(file)
                            fail_count += 1
                            continue
            temp_path = path

    if fail_count > 0:
            f = open("log.txt", "w")
            print ("%d Errors occurred during conversion. Check log.txt for details" % fail_count)
            f.write("The following files were successfully converted:\n")
            for s in success:
                    f.write("\t-%s\n" % s)

            f.write("\n\nThe following files failed to be converted:\n")
            for a in failure:
                    f.write("\t-%s\n" % a)
            f.close()
    else:
            print "All files converted successfully!"


def usage():
    print "usage:  dostuff.py [hi:]\n \
          \t -h\t print usage\n \
          \t -i\t directory path\n"
    sys.exit(2)

def main(argv):

    if(len(argv) == 0):
            usage()

    path = ''

    try:
            opts, args = getopt.getopt(argv,"hi:",["path="])
    except getopt.GetoptError:
            usage()

    for opt, arg in opts:
            if opt == '-h':
                    usage()
elif opt in ("-i", "--ifile"):
                    path = arg
    if path.endswith('/') == False:
            path += '/'

    scan_dir(path)


if __name__ == "__main__":
    main(sys.argv[1:])