Pydev 中的 "Module: CLI (argparse)" 模板是如何工作的？

Question

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

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

您运行处于 DEBUG 模式，您在该模式下所做的只是将内容附加到 argv:

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

由于您要添加 "unknown" 参数，当您运行:

args = parser.parse_args()

它引发了一个异常。您可以通过删除该行（最好）或使用：

来解决它

parser.parse_known_args([])

（后者是隐藏潜在问题的补丁，应谨慎使用。IMO，在这种情况下不应使用它！）。

Answer 2

在DEBUG模式下，-h添加到sys.argv。它优先于所有其他输入，产生 help 消息（并退出）。

注释掉将 -h 添加到 DEBUG 的行以查看参数的效果（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中的那些）。

Pydev 中的 "Module: CLI (argparse)" 模板是如何工作的？

How does the "Module: CLI (argparse)" template in Pydev work?

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