Pydev 中的"Module: CLI (argparse)"模板如何工作？

Question

Pydev (Eclipse)中的"Module: CLI (argparse)"模板如何工作?当我运行它时，它只是打印出用法帮助并退出，我的代码没有被执行。正如我从使用输出中理解的那样，我需要传递一个'path'参数。但是当我设置路径时，我得到了相同的结果。

模板如下所示:

#!/usr/local/bin/python2.7
# encoding: utf-8
'''
test1.test -- shortdesc
test1.test is a description
It defines classes_and_methods
@author:     user_name
@copyright:  2015 organization_name. All rights reserved.
@license:    license
@contact:    user_email
@deffield    updated: Updated
'''
import sys
import os
from argparse import ArgumentParser
from argparse import RawDescriptionHelpFormatter
__all__ = []
__version__ = 0.1
__date__ = '2015-07-31'
__updated__ = '2015-07-31'
DEBUG = 1
TESTRUN = 0
PROFILE = 0
class CLIError(Exception):
    '''Generic exception to raise and log different fatal errors.'''
    def __init__(self, msg):
        super(CLIError).__init__(type(self))
        self.msg = "E: %s" % msg
    def __str__(self):
        return self.msg
    def __unicode__(self):
        return self.msg
def main(argv=None): # IGNORE:C0111
    '''Command line options.'''
    if argv is None:
        argv = sys.argv
    else:
        sys.argv.extend(argv)
    program_name = os.path.basename(sys.argv[0])
    program_version = "v%s" % __version__
    program_build_date = str(__updated__)
    program_version_message = '%%(prog)s %s (%s)' % (program_version, program_build_date)
    program_shortdesc = __import__('__main__').__doc__.split("n")[1]
    program_license = '''%s
  Created by user_name on %s.
  Copyright 2015 organization_name. All rights reserved.
  Licensed under the Apache License 2.0
  http://www.apache.org/licenses/LICENSE-2.0
  Distributed on an "AS IS" basis without warranties
  or conditions of any kind, either express or implied.
USAGE
''' % (program_shortdesc, str(__date__))
    try:
        # Setup argument parser
        parser = ArgumentParser(description=program_license, formatter_class=RawDescriptionHelpFormatter)
        parser.add_argument("-r", "--recursive", dest="recurse", action="store_true", help="recurse into subfolders [default: %(default)s]")
        parser.add_argument("-v", "--verbose", dest="verbose", action="count", help="set verbosity level [default: %(default)s]")
        parser.add_argument("-i", "--include", dest="include", help="only include paths matching this regex pattern. Note: exclude is given preference over include. [default: %(default)s]", metavar="RE" )
        parser.add_argument("-e", "--exclude", dest="exclude", help="exclude paths matching this regex pattern. [default: %(default)s]", metavar="RE" )
        parser.add_argument('-V', '--version', action='version', version=program_version_message)
        parser.add_argument(dest="paths", help="paths to folder(s) with source file(s) [default: %(default)s]", metavar="path", nargs='+')
        # Process arguments
        args = parser.parse_args()
        paths = args.paths
        verbose = args.verbose
        recurse = args.recurse
        inpat = args.include
        expat = args.exclude
        if verbose > 0:
            print("Verbose mode on")
            if recurse:
                print("Recursive mode on")
            else:
                print("Recursive mode off")
        if inpat and expat and inpat == expat:
            raise CLIError("include and exclude pattern are equal! Nothing will be processed.")
        for inpath in paths:
            ### do something with inpath ###
            print(inpath)
        return 0
    except KeyboardInterrupt:
        ### handle keyboard interrupt ###
        return 0
    except Exception, e:
        if DEBUG or TESTRUN:
            raise(e)
        indent = len(program_name) * " "
        sys.stderr.write(program_name + ": " + repr(e) + "n")
        sys.stderr.write(indent + "  for help use --help")
        return 2
if __name__ == "__main__":
    if DEBUG:
        sys.argv.append("-h")
        sys.argv.append("-v")
        sys.argv.append("-r")
    if TESTRUN:
        import doctest
        doctest.testmod()
    if PROFILE:
        import cProfile
        import pstats
        profile_filename = 'test1.test_profile.txt'
        cProfile.run('main()', profile_filename)
        statsfile = open("profile_stats.txt", "wb")
        p = pstats.Stats(profile_filename, stream=statsfile)
        stats = p.strip_dirs().sort_stats('cumulative')
        stats.print_stats()
        statsfile.close()
        sys.exit(0)
    sys.exit(main())

Answer 1

在DEBUG模式下，-h添加到sys.argv。它具有高于所有其他输入的优先级，产生help消息(并退出)。

注释掉将-h添加到DEBUG以查看参数效果的那行(加上v和r)

在其他模式下(main中定义的模式除外)，命令行参数应该有效(即sys.argv中的参数)。

Answer 2

你在调试模式下运行，你在那个模式下所做的就是把东西附加到argv:

if DEBUG:
        sys.argv.append("-h") # <-- that is your problem
        sys.argv.append("-v")
        sys.argv.append("-r")

因为你添加了一个"unknown"参数，当你运行:

args = parser.parse_args()

会引发异常。您可以通过删除该行来解决它(最好)，或者使用:

parser.parse_known_args([])

(后者是隐藏潜在问题的补丁，应谨慎使用)。在我看来，它不应该在这种情况下使用!)