如何向Python Argparse默认帮助信息中添加自定义文本？

Got it, adding a custom section like additional information to argparse's help output is totally doable—here are two approaches depending on how polished you want the result to be:

1. Quick & Simple: Use the epilog Parameter #

If you just need a fast solution without custom classes, argparse's built-in epilog parameter lets you tack extra text at the end of the help output. You can format it to look like a proper section with a heading and indentation:

import argparse

parser = argparse.ArgumentParser(
    prog='ProgramName',
    description='Your program description goes here',
    # Define your custom section directly in the epilog
    epilog='\nadditional information:\n  This will show additional information...\n  You can add multiple indented lines for extra details, like usage examples or notes.'
)

# Add your regular arguments
parser.add_argument('input_file', help='Path to your input file')
parser.add_argument('-v', '--verbose', action='store_true', help='Enable verbose logging')

# Test the help output
parser.print_help()

The output will look like this:

usage: ProgramName [-h] [-v] input_file

Your program description goes here

positional arguments:
input_file Path to your input file

optional arguments:
-h, --help show this help message and exit
-v, --verbose Enable verbose logging

additional information:
This will show additional information...
You can add multiple indented lines for extra details, like usage examples or notes.

2. Polished & Consistent: Custom Help Formatter #

If you want the custom section to match the exact formatting of argparse's default sections (same heading style, indentation, etc.), you can create a custom HelpFormatter by inheriting from argparse's default class. This lets you integrate your section seamlessly:

import argparse

class CustomHelpFormatter(argparse.HelpFormatter):
    def _format_custom_section(self, heading, text):
        # Reuse argparse's built-in formatting logic for consistency
        formatted_heading = self._format_heading(heading) if heading else ""
        formatted_text = self._format_text(text) if text else ""
        return formatted_heading + formatted_text + '\n'

    def add_custom_section(self, heading, text):
        # Add the custom section to the help content
        self._add_item(self._format_custom_section, (heading, text))

# Initialize the parser with your custom formatter
parser = argparse.ArgumentParser(
    prog='ProgramName',
    description='Your program description here',
    formatter_class=CustomHelpFormatter
)

# Add your standard arguments
parser.add_argument('pos_arg', help='A required positional argument')
parser.add_argument('-o', '--output', help='Path to save the output file')

# Get the formatter instance and add your custom section
formatter = parser._get_formatter()
formatter.add_custom_section(
    'additional information',
    'This will show additional information...\n\nYou can include detailed notes, step-by-step examples, or important usage warnings here. The format will match argparse\'s default sections perfectly.'
)

# Generate and print the fully formatted help
print(formatter.format_help())

This approach ensures your new section blends in with the rest of the help output, making it look professional and consistent with argparse's native style.

内容的提问来源于stack exchange，提问作者Yoavhayun