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在argparse中带有破折号的选项

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问题：在argparse中带有破折号的选项
回答 0
回答 1
回答 2

问题：在argparse中带有破折号的选项

我想在argparse模块中有一些选项，例如，--pm-export当我尝试使用它时，就像args.pm-export出现没有属性的错误一样pm。我该如何解决这个问题？-命令行选项中可以有吗？

点击查看英文原文

I want to have some options in argparse module such as --pm-export however when I try to use it like args.pm-export I get the error that there is not attribute pm. How can I get around this issue? Is it possible to have - in command line options?

回答 0

由于在指定的argparse文档：

对于可选的参数操作，通常从选项字符串中推断出dest的值。ArgumentParser通过获取第一个long选项字符串并剥离初始--字符串来生成dest的值。任何内部-字符都将转换为_字符，以确保字符串是有效的属性名称

因此，您应该使用args.pm_export。

点击查看英文原文

As indicated in the argparse docs:

For optional argument actions, the value of dest is normally inferred from the option strings. ArgumentParser generates the value of dest by taking the first long option string and stripping away the initial -- string. Any internal - characters will be converted to _ characters to make sure the string is a valid attribute name

So you should be using args.pm_export.

回答 1

不幸的是，短划线到下划线的替换不适用于位置参数（不带前缀--），例如

parser = argparse.ArgumentParser(description='Process some integers.')
parser.add_argument('logs-dir',
                    help='Directory with .log and .log.gz files')
parser.add_argument('results-csv', type=argparse.FileType('w'),
                    default=sys.stdout,
                    help='Output .csv filename')
args = parser.parse_args()
print args

# gives
# Namespace(logs-dir='./', results-csv=<open file 'lool.csv', mode 'w' at 0x9020650>)

因此，您应该使用第一个参数add_argument()作为属性名称，并使用metavarkwarg设置它在帮助中的外观：

parser = argparse.ArgumentParser(description='Process some integers.')
parser.add_argument('logs_dir', metavar='logs-dir',
                    nargs=1,
                    help='Directory with .log and .log.gz files')
parser.add_argument('results_csv', metavar='results-csv',
                    nargs=1,
                    type=argparse.FileType('w'),
                    default=sys.stdout,
                    help='Output .csv filename')
args = parser.parse_args()
print args

# gives
# Namespace(logs_dir=['./'], results_csv=[<open file 'lool.csv', mode 'w' at 0xb71385f8>])
点击查看英文原文

Unfortunately, dash-to-underscore replacement doesn’t work for positionalarguments (not prefixed by --) like

parser = argparse.ArgumentParser(description='Process some integers.')
parser.add_argument('logs-dir',
                    help='Directory with .log and .log.gz files')
parser.add_argument('results-csv', type=argparse.FileType('w'),
                    default=sys.stdout,
                    help='Output .csv filename')
args = parser.parse_args()
print args

# gives
# Namespace(logs-dir='./', results-csv=<open file 'lool.csv', mode 'w' at 0x9020650>)

So, you should use 1’st argument to add_argument() as attribute name and metavar kwarg to set how it should look in help:

parser = argparse.ArgumentParser(description='Process some integers.')
parser.add_argument('logs_dir', metavar='logs-dir',
                    nargs=1,
                    help='Directory with .log and .log.gz files')
parser.add_argument('results_csv', metavar='results-csv',
                    nargs=1,
                    type=argparse.FileType('w'),
                    default=sys.stdout,
                    help='Output .csv filename')
args = parser.parse_args()
print args

# gives
# Namespace(logs_dir=['./'], results_csv=[<open file 'lool.csv', mode 'w' at 0xb71385f8>])

回答 2

破折号转换为下划线：

import argparse
pa = argparse.ArgumentParser()
pa.add_argument('--foo-bar')
args = pa.parse_args(['--foo-bar', '24'])
print args # Namespace(foo_bar='24')
点击查看英文原文

Dashes are converted to underscores:

import argparse
pa = argparse.ArgumentParser()
pa.add_argument('--foo-bar')
args = pa.parse_args(['--foo-bar', '24'])
print args # Namespace(foo_bar='24')