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Author Topic: Bullet Help Formatter for Python’s argparse  (Read 2885 times)


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Bullet Help Formatter for Python’s argparse
« on: July 02, 2016, 02:55:20 AM »

Original post for Bullet Help Formatter for Python’s argparse can be found at https://www.castledragmire.com/Posts/Bullet_Help_Formatter_for_Python’s_argparse.
Originally posted on: 07/02/16

This is a HelpFormatter for Python’s argparse class which:
  • Takes raw input and wraps long lines to indent against the current line start.
  • When an indented/list line is encountered, which starts with spaces followed by a star "*", wrapped line’s indents will start 2 spaces after the star.
  • Lines attempt to split at words of 10 characters or less (see .MinCharsInSplitWord).
  • If a line needs to split along a word longer than this, a hyphen is inserted at the end of the line.

import argparse
import re
class BulletHelpFormatter(argparse.HelpFormatter):
   def __init__(self, *args, **kwargs):
       super(BulletHelpFormatter, self).__init__(*args, **kwargs)

   def _split_lines(self, text, width):
       #Split lines around line breaks and then modify each line
       for Line in text.splitlines():
           #Get the number of spaces to put at subsequent lines
           #0 if not a list item, oherwise, 2+list item start
           ListEl=re.match(r'^ *\*', Line)
           NumBeginningSpace=(0 if ListEl==None else ListEl.end()+1)

           #Add extra spaces at the beginning of each line to match the start of the current line, and go to a maxium of $width
               #Get the word break points before and after where the line would end
               MaxLineLen=max(min(width-NumSpacesToAdd, len(Line)), 1)
               for WordBreak in re.finditer(r'(?<=\W).|\W|$', Line):
                   if CurWordBreak>=MaxLineLen:
                       if CurWordBreak==MaxLineLen:

               #If previous wordbreak is more than MinCharsInSplitWord away from MaxLineLen, then split at the end of the line
               IsSplit=(PrevWordBreak<1 or CurWordBreak-PrevWordBreak>self.MinCharsInSplitWord)
               SplitPos=(MaxLineLen if IsSplit else PrevWordBreak)

               #Append the new line to the list of lines
               Lines.append(SpacesToAdd+Line[0:SplitPos]+('-' if IsSplit else ''))

               #If this is the end, nothing left to do
               if len(Line)==0:

               #If this is the first pass, update line creation variables
               if IsFirstPass:
                   SpacesToAdd=(' ' * NumSpacesToAdd)

       return Lines