A script for Taskpaper files that sets tasks as @done if all subtasks are complete. This is purely a test. It would have to be added to in order to grab and parse *.taskpaper files.

taskpaper-completer.py

#! /usr/bin/env python
# -*- coding: UTF-8 -*-

import re

# imput string sample data
targ = '''	- Task 09
	This is a comment
		- Subtask 9.01 @done
		This is a subtask comment
		- Subtask 9.02
		Another comment
			- Subsubtask 9.01 @done
			- Subsubtask 9.02 @done
			Why so many comments?
			- Subsubtask 9.03
				- Subsubsubtask 9.01 @done
				Just another comment to break your code
				- Subsubsubtask 9.02
				Break, break, break
					- Subsubsubsubtask 9.01 @done
					This is the last comment, I promise
				- Subsubsubtask 9.03 @done
				I lied.
			- This is the task of interest
				- Subsubsubtask 9.03 @done
				I love lying
			- Subsubtask 9.05 @done
		- Subtask 9.03 @done
		Ok, this is truly the last comment.
		Nah.'''

# original format from @philgr
# targ = '\t- Task 09\n\tThis is a comment\n\t\t- Subtask 9.01 @done\n\t\tThis is a subtask comment\n\t\t- Subtask 9.02\n\t\tAnother comment\n\t\t\t- Subsubtask 9.01 @done\n\t\t\t- Subsubtask 9.02 @done\n\t\t\tWhy so many comments?\n\t\t\t- Subsubtask 9.03\n\t\t\t\t- Subsubsubtask 9.01 @done\n\t\t\t\tJust another comment to break your code\n\t\t\t\t- Subsubsubtask 9.02\n\t\t\t\tBreak, break, break\n\t\t\t\t\t- Subsubsubsubtask 9.01 @done\n\t\t\t\t\tThis is the last comment, I promise\n\t\t\t\t- Subsubsubtask 9.03 @done\n\t\t\t\tI lied.\n\t\t\t- This is the task of interest\n\t\t\t\t- Subsubsubtask 9.03 @done\n\t\t\t\tI love lying\n\t\t\t- Subsubtask 9.05 @done\n\t\t- Subtask 9.03 @done\n\t\tOk, this is truly the last comment.\n\t\tNah.'


revtarg = targ.split('\n')[::-1] # targ is split and reversed
leading_spaces = 0 # set a variable for leading whitespace

# set a list of True booleans. This is how we track subtask completion.
# if a subtask isn't complete, the boolean at that tab count will be set to False.
# since this is Taskpaper, assume tab indents. If leading white space is spaces, increase the number to 50 or more.
tabtracker = [True]*20

# iterate over each line. Remember that they are in reverse order.
for i in range(len(revtarg)):
	# get the white space count
	thisline_spaces = len(revtarg[i]) - len(revtarg[i].lstrip())
	
	# only work on tasks
	if re.search("^\t*- ",revtarg[i]):
		# If task isn't done, track it.
		if not re.search("@done",revtarg[i]):
			
			# if the line is outdented AND the subtasks are done, set task to done.
			if (leading_spaces > thisline_spaces) and tabtracker[leading_spaces]==True:
				revtarg[i] = revtarg[i] + " @done"
			else: # anything that doesn't match should be marked as False
				tabtracker[thisline_spaces] = False
		
		# get the current leading space before starting the next line.
		leading_spaces = thisline_spaces

print '\n'.join(revtarg[::-1])