我在Python 2.7中使用argparse来解析输入选项。我的选项之一是多项选择。我想在它的帮助文本中做一个列表。
from argparse import ArgumentParser
parser = ArgumentParser(description='test')
parser.add_argument('-g', choices=['a', 'b', 'g', 'd', 'e'], default='a',
help="Some option, where\n"
" a = alpha\n"
" b = beta\n"
" g = gamma\n"
" d = delta\n"
" e = epsilon")
parser.parse_args()
然而，argparse会删除所有换行和连续的空格。结果如下所示
~/Downloads:52$ python2.7 x.py -h
usage: x.py [-h] [-g {a,b,g,d,e}]
test
optional arguments:
-h, --help show this help message and exit
-g {a,b,g,d,e} Some option, where a = alpha b = beta g = gamma d = delta e
= epsilon
如何在帮助文本中插入换行?
我承认我发现这是一个非常令人沮丧的经历，因为我看到很多解决方案，我在网上看到很多次这样的问题。但我发现这些解决方案对我来说太复杂了，我想分享我最简单的解决方案。
下面是演示的脚本:
#!/usr/bin/python3
import textwrap
from argparse import ArgumentParser, HelpFormatter
class RawFormatter(HelpFormatter):
def _fill_text(self, text, width, indent):
return "\n".join([textwrap.fill(line, width) for line in textwrap.indent(textwrap.dedent(text), indent).splitlines()])
program_descripton = f'''
FunkyTool v1.0
Created by the Funky Guy on January 1 2020
Copyright 2020. All rights reserved.
Licensed under The Hippocratic License 2.1
https://firstdonoharm.dev/
Distributed on an "AS IS" basis without warranties
or conditions of any kind, either express or implied.
USAGE:
'''
parser = ArgumentParser(description=program_descripton, formatter_class=RawFormatter)
args = parser.parse_args()
下面是它在test.py中的样子:
$ ./test.py --help
usage: test.py [-h]
FunkyTool v1.0
Created by the Funky Guy on January 1 2020
Copyright 2020. All rights reserved.
Licensed under The Hippocratic License 2.1
https://firstdonoharm.dev/
Distributed on an "AS IS" basis without warranties
or conditions of any kind, either express or implied.
USAGE:
optional arguments:
-h, --help show this help message and exit
所以，所有原始描述中的基本格式都被整齐地保留了下来，我们不得不，唉，使用一个自定义格式化器，但它是一个联机程序。它可以写得更清楚:
class RawFormatter(HelpFormatter):
def _fill_text(self, text, width, indent):
text = textwrap.dedent(text) # Strip the indent from the original python definition that plagues most of us.
text = textwrap.indent(text, indent) # Apply any requested indent.
text = text.splitlines() # Make a list of lines
text = [textwrap.fill(line, width) for line in text] # Wrap each line
text = "\n".join(text) # Join the lines again
return text
但我自己更喜欢写在一行上。
我想在描述文本中有手动换行符，并自动换行;但是这里没有一个建议对我有用-所以我最终修改了答案中给出的SmartFormatter类;尽管argparse方法名不是一个公共API，但这是我拥有的(作为一个名为test.py的文件):
import argparse
from argparse import RawDescriptionHelpFormatter
# call with: python test.py -h
class SmartDescriptionFormatter(argparse.RawDescriptionHelpFormatter):
#def _split_lines(self, text, width): # RawTextHelpFormatter, although function name might change depending on Python
def _fill_text(self, text, width, indent): # RawDescriptionHelpFormatter, although function name might change depending on Python
#print("splot",text)
if text.startswith('R|'):
paragraphs = text[2:].splitlines()
rebroken = [argparse._textwrap.wrap(tpar, width) for tpar in paragraphs]
#print(rebroken)
rebrokenstr = []
for tlinearr in rebroken:
if (len(tlinearr) == 0):
rebrokenstr.append("")
else:
for tlinepiece in tlinearr:
rebrokenstr.append(tlinepiece)
#print(rebrokenstr)
return '\n'.join(rebrokenstr) #(argparse._textwrap.wrap(text[2:], width))
# this is the RawTextHelpFormatter._split_lines
#return argparse.HelpFormatter._split_lines(self, text, width)
return argparse.RawDescriptionHelpFormatter._fill_text(self, text, width, indent)
parser = argparse.ArgumentParser(formatter_class=SmartDescriptionFormatter, description="""R|Blahbla bla blah blahh/blahbla (bla blah-blabla) a blahblah bl a blaha-blah .blah blah
Blah blah bla blahblah, bla blahblah blah blah bl blblah bl blahb; blah bl blah bl bl a blah, bla blahb bl:
blah blahblah blah bl blah blahblah""")
options = parser.parse_args()
这是它在2.7和3.4中的工作原理:
$ python test.py -h
usage: test.py [-h]
Blahbla bla blah blahh/blahbla (bla blah-blabla) a blahblah bl a blaha-blah
.blah blah
Blah blah bla blahblah, bla blahblah blah blah bl blblah bl blahb; blah bl
blah bl bl a blah, bla blahb bl:
blah blahblah blah bl blah blahblah
optional arguments:
-h, --help show this help message and exit
如果你只是想覆盖一个选项，你不应该使用RawTextHelpFormatter。相反，子类化HelpFormatter并为应该处理“原始”的选项提供一个特殊的介绍(我使用“R|rest of help”):
import argparse
class SmartFormatter(argparse.HelpFormatter):
def _split_lines(self, text, width):
if text.startswith('R|'):
return text[2:].splitlines()
# this is the RawTextHelpFormatter._split_lines
return argparse.HelpFormatter._split_lines(self, text, width)
并使用它:
from argparse import ArgumentParser
parser = ArgumentParser(description='test', formatter_class=SmartFormatter)
parser.add_argument('-g', choices=['a', 'b', 'g', 'd', 'e'], default='a',
help="R|Some option, where\n"
" a = alpha\n"
" b = beta\n"
" g = gamma\n"
" d = delta\n"
" e = epsilon")
parser.parse_args()
对.add_argument()的任何其他调用，其中帮助不是以R|开始的，将被正常包装。
这是我对argparse改进的一部分。完整的SmartFormatter也支持添加
所有选项的默认值，以及实用程序描述的原始输入。完整版
有它自己的_split_lines方法，这样对版本字符串所做的任何格式化都会被保留:
parser.add_argument('--version', '-v', action="version",
version="version...\n 42!")
我承认我发现这是一个非常令人沮丧的经历，因为我看到很多解决方案，我在网上看到很多次这样的问题。但我发现这些解决方案对我来说太复杂了，我想分享我最简单的解决方案。
下面是演示的脚本:
#!/usr/bin/python3
import textwrap
from argparse import ArgumentParser, HelpFormatter
class RawFormatter(HelpFormatter):
def _fill_text(self, text, width, indent):
return "\n".join([textwrap.fill(line, width) for line in textwrap.indent(textwrap.dedent(text), indent).splitlines()])
program_descripton = f'''
FunkyTool v1.0
Created by the Funky Guy on January 1 2020
Copyright 2020. All rights reserved.
Licensed under The Hippocratic License 2.1
https://firstdonoharm.dev/
Distributed on an "AS IS" basis without warranties
or conditions of any kind, either express or implied.
USAGE:
'''
parser = ArgumentParser(description=program_descripton, formatter_class=RawFormatter)
args = parser.parse_args()
下面是它在test.py中的样子:
$ ./test.py --help
usage: test.py [-h]
FunkyTool v1.0
Created by the Funky Guy on January 1 2020
Copyright 2020. All rights reserved.
Licensed under The Hippocratic License 2.1
https://firstdonoharm.dev/
Distributed on an "AS IS" basis without warranties
or conditions of any kind, either express or implied.
USAGE:
optional arguments:
-h, --help show this help message and exit
所以，所有原始描述中的基本格式都被整齐地保留了下来，我们不得不，唉，使用一个自定义格式化器，但它是一个联机程序。它可以写得更清楚:
class RawFormatter(HelpFormatter):
def _fill_text(self, text, width, indent):
text = textwrap.dedent(text) # Strip the indent from the original python definition that plagues most of us.
text = textwrap.indent(text, indent) # Apply any requested indent.
text = text.splitlines() # Make a list of lines
text = [textwrap.fill(line, width) for line in text] # Wrap each line
text = "\n".join(text) # Join the lines again
return text
但我自己更喜欢写在一行上。
使用RawTextHelpFormatter获取新行并处理缩进的另一种简单方法是
import argparse
parser = argparse.ArgumentParser(
description='test', formatter_class=argparse.RawTextHelpFormatter)
parser.add_argument('-g', choices=['a', 'b', 'g', 'd', 'e'], default='a',
help=('Some option, where\n'
' a = alpha\n'
' b = beta\n'
' g = gamma\n'
' d = delta\n'
' e = epsilon'))
parser.parse_args()
输出为
$ python2 x.py -h
usage: x.py [-h] [-g {a,b,g,d,e}]
test
optional arguments:
-h, --help show this help message and exit
-g {a,b,g,d,e} Some option, where
a = alpha
b = beta
g = gamma
d = delta
e = epsilon
