Reputation: 555
import argparse
parser = argparse.ArgumentParser(prog='tool')
args = [('-u', '--upf', 'ref. upf', dict(required='True')),
('-s', '--skew', 'ref. skew', {}),
('-m', '--model', 'ref. model', {})]
for args1, args2, desc, options in args:
parser.add_argument(args1, args2, help=desc, **options)
parser.print_help()
Output:
usage: capcheck [-h] -u UPF [-s SKEW] [-m MODEL]
optional arguments:
-h, --help show this help message and exit
-u UPF, --upf UPF ref. upf
-s SKEW, --skew SKEW ref. skew
-m MODEL, --model MODEL
ref. model
How do I print ref. model in the same line as -m MODEL, --model MODEL
instead of that appearing on a separate line when I run the script with -h
option?
Upvotes: 47
Views: 26062
Reputation: 31
As the argparse library tries to use the COLUMNS
environment variable to get the terminal width, we also can set this variable, and let argparse do its job.
import os
import argparse
rows, columns = os.popen('stty size', 'r').read().split()
os.environ["COLUMNS"] = str(columns)
parser = argparse.ArgumentParser(etc...
Tested and approved on RHEL/Python 2.7.5
Credits to https://stackoverflow.com/a/943921 for getting the real terminal width
Upvotes: 2
Reputation: 6915
If you are providing a custom formatter_class
to your ArgumentParser
parser = argparse.ArgumentParser(formatter_class=help_formatter)
and then use subparsers, the formatter will only apply to the top-level help message. In order to use the same (or some other) formatter for all subparsers, you need to provide formatter_class
argument for each add_parser
call:
subparsers = parser.add_subparsers(metavar="ACTION", dest="action")
child_parser = subparsers.add_parser(
action_name, formatter_class=help_formatter
)
Upvotes: 2
Reputation: 11
Another approach: hijack sys.argv, check it for --help and -h, if found extract help text using argparse.format_help, massage it, print it, and exit.
import sys, re, argparse
RGX_MID_WS = re.compile(r'(\S)\s{2,}')
def main(argv):
# note add_help = False
parser = argparse.ArgumentParser(description = '%(prog)s: testing help mods', formatter_class= argparse.RawTextHelpFormatter, add_help = False)
parser.add_argument('bar', nargs='+', help='two bars that need to be frobbled')
parser.add_argument('--foo', action='store_true', help='foo the bars before frobbling\nfoo the bars before frobbling')
parser.add_argument('--xxxxx', nargs=2, help='many xes')
parser.add_argument('--bacon', help ='a striped food')
parser.add_argument('--badger', help='in a striped pyjamas')
parser.add_argument('--animal', dest='animal', choices=('zabra', 'donkey', 'bat') ,help ='could be one of these')
# may exit
lArgs = help_manage(parser)
args = parser.parse_args() # args = lArgs
print('bars are: ', args.bar)
def help_manage(parser):
"""
check for -h, --help, -h in a single-letter cluster;
if none found, return, otherwise clean up help text and exit
"""
lArgs = sys.argv[1:]
lArgsNoHelp = [sOpt for sOpt in lArgs if (not sOpt in ('--help', '-h')) and not (sOpt[0] == '-' and sOpt[1] != '-' and 'h' in sOpt)]
# no change? then no --help params
if len(lArgsNoHelp) == len(lArgs): return
sHelp = parser.format_help()
# to see help as formated by argparse, uncomment:
# print(sHelp)
# exit()
for sLine in sHelp.split('\n'): print(clean_line(sLine))
exit()
def clean_line(sLine):
"""
this is just an example, and goes nowhere near covering all possible
argument properties
"""
# avoid messing with usage: lines
if 'usage' in sLine: return sLine
if sLine.startswith(' ') and '[' in sLine: return sLine
if sLine.endswith(' arguments:'): return sLine + '\n'
sLine = sLine.lstrip()
sLine = RGX_MID_WS.sub(r'\1\n', sLine)
if sLine.startswith('-'): sLine = '\n' + sLine
return sLine.replace('{', '\n(can be: ').replace('}', ')').replace('\n\n', '\n')
if __name__ == '__main__':
bRes = main(sys.argv[1:])
sys.exit(bRes)
Help without formatting:
usage: argparse_fix_min2.py [--foo] [--xxxxx XXXXX XXXXX] [--bacon BACON]
[--badger BADGER] [--animal {zabra,donkey,bat}]
bar [bar ...]
argparse_fix_min2.py: testing help mods
positional arguments:
bar two bars that need to be frobbled
optional arguments:
--foo foo the bars before frobbling
foo the bars before frobbling
--xxxxx XXXXX XXXXX many xes
--bacon BACON a striped food
--badger BADGER in a striped pyjamas
--animal {zabra,donkey,bat}
could be one of these
with formatting:
usage: argparse_fix_min2.py [--foo] [--xxxxx XXXXX XXXXX] [--bacon BACON]
[--badger BADGER] [--animal {zabra,donkey,bat}]
bar [bar ...]
argparse_fix_min2.py: testing help mods
positional arguments:
bar
two bars that need to be frobbled
optional arguments:
--foo
foo the bars before frobbling
foo the bars before frobbling
--xxxxx XXXXX XXXXX
many xes
--bacon BACON
a striped food
--badger BADGER
in a striped pyjamas
--animal
(can be: zabra,donkey,bat)
could be one of these
"""
Upvotes: 0
Reputation: 5873
Inspired by @jfs's answer, I have come up with this solution:
def make_wide(formatter, w=120, h=36):
"""Return a wider HelpFormatter, if possible."""
try:
# https://stackoverflow.com/a/5464440
# beware: "Only the name of this class is considered a public API."
kwargs = {'width': w, 'max_help_position': h}
formatter(None, **kwargs)
return lambda prog: formatter(prog, **kwargs)
except TypeError:
warnings.warn("argparse help formatter failed, falling back.")
return formatter
Having that, you can call it with any HelpFormatter
that you like:
parser = argparse.ArgumentParser(
formatter_class=make_wide(argparse.ArgumentDefaultsHelpFormatter)
)
or
parser = argparse.ArgumentParser(
formatter_class=make_wide(argparse.HelpFormatter, w=140, h=20)
)
What this does is make sure that the wider formatter can actually be created using the width
and max_help_position
arguments. If the private API changes, that is noted by make_wide
by a TypeError
and the formatter is returned unchanged. That should make the code more reliable for deployed applications.
I'd welcome any suggestions to make this more pythonic.
Upvotes: 9
Reputation: 414915
You could supply formatter_class
argument:
parser = argparse.ArgumentParser(prog='tool',
formatter_class=lambda prog: argparse.HelpFormatter(prog,max_help_position=27))
args = [('-u', '--upf', 'ref. upf', dict(required='True')),
('-s', '--skew', 'ref. skew', {}),
('-m', '--model', 'ref. model', {})]
for args1, args2, desc, options in args:
parser.add_argument(args1, args2, help=desc, **options)
parser.print_help()
Note: Implementation of argparse.HelpFormatter
is private only the name is public. Therefore the code might stop working in future versions of argparse
. File a feature request to provide a public interface for the customization of max_help_position
on http://bugs.python.org/
usage: tool [-h] -u UPF [-s SKEW] [-m MODEL]
optional arguments:
-h, --help show this help message and exit
-u UPF, --upf UPF ref. upf
-s SKEW, --skew SKEW ref. skew
-m MODEL, --model MODEL ref. model
Upvotes: 51