% in documentation breaks Argumentparser

[BIRDSLab]

Bug report

Bug description:

from argparse import ArgumentParser
parser = ArgumentParser()
parser.add_argument(
    "-v", dest="verbose", 
    help="duck around %", 
    action='store_true' 
)    
# Find out
options = parser.parse_args()

Run this with a '-h' on the commandline, and watch the pretty backtrace

CPython versions tested on:

3.10

Operating systems tested on:

Linux

[ZeroIntensity]

This is intended, % is used for format strings. To escape it, use %% (see the docs):

parser.add_argument(
    "-v", dest="verbose", 
    help="duck around %%",
    action='store_true' 
)    

[terryjreedy]

Please ask about puzzling behavior on https://discuss.python.org/c/help/7, where answers are more visible to others.