Python argparse help formatter that keeps new lines and doesn't break words (so URLs are preserved), but still wraps lines. Use with: `argparse.ArgumentParser(formatter_class=SmartFormatter)`

smart_formatter.py

import argparse
from typing import List

class SmartFormatter(argparse.HelpFormatter):
    def _split_lines(self, text: str, width: int) -> List[str]:
        lines: List[str] = []
        for line_str in text.split('\n'):
            line: List[str] = []
            line_len = 0
            for word in line_str.split():
                word_len = len(word)
                next_len = line_len + word_len
                if line: next_len += 1
                if next_len > width:
                    lines.append(' '.join(line))
                    line.clear()
                    line_len = 0
                elif line:
                    line_len += 1

                line.append(word)
                line_len += word_len

            lines.append(' '.join(line))
        return lines
    
    def _fill_text(self, text: str, width: int, indent: str) -> str:
        return '\n'.join(indent + line for line in self._split_lines(text, width - len(indent)))

Thanks for sharing this! You just saved me a ton of time!

Thank you so much for this!