Custom Column: Template Error Python

[Wiggo]

With Calibre 9.10.0 I get this error in book details for two of my custom columns.

#Realname

Spoiler:

python:
def evaluate(book, context):
	from collections import defaultdict
	from calibre.utils.icu import sort_key

	alias_category = 'Pseudo.'
	alias_len = len(alias_category)
	fake_comma = '⸴'

	db = context.db.new_api
	aliases = defaultdict(list)
	# Parse the user categories, getting the real names. Build an inverted dict
	# pen_name: list(real_names). Why a list? Because a pen name can be used by
	# more than one real author.
	for real_name,pen_names in {cat[alias_len:]:vals
			for cat,vals in db.pref('user_categories').items()
				if cat.startswith(alias_category)}.items():
		for pn in pen_names:
			aliases[pn[0]].append(real_name)

	# For each author (pen name) for this book, get the real author(s)
	ans = set()
	for aut in book.authors:
		if aut in aliases:
			for real_name in aliases[aut]:
				# Replace commas with a fake comma because commas are used 
				# by calibre to separate values
				ans.add(real_name.replace(',', fake_comma) )
	return ', '.join(sorted(ans, key=sort_key))

#Alias

Spoiler:

python:
def evaluate(book, context):
	from collections import defaultdict
	from calibre.utils.icu import sort_key

	alias_category = 'Pseudo.'
	link_break = '<br/>'

	db = context.db.new_api

	# Build a set of other pen names for each author that is a pen name.
	# This loop only processes categories prefixed with alias_category
	all_pen_names = defaultdict(set)
	for pen_names in [[v[0] for v in vals]
			for cat,vals in db.pref('user_categories').items()
				if cat.startswith(alias_category)]:
		for pn in pen_names:
			all_pen_names[pn].update(pen_names)

	# Build the set of all pen names for all the authors of this book. Use a set
	# to remove duplicates.
	auts = set()
	for p in book.authors:
		if p in all_pen_names:
			auts.update(all_pen_names[p])

	# Now build the list of calibre search link URLs , one for each pen name.
	ans = list()
	for p in sorted(auts, key=sort_key): 
		# Replace any spaces with non-breaking spaces to prevent a name from
		# wrapping over two lines.
		ans.append(f'''<a href="calibre://search/_?eq='''
			f'''{('authors:"='+p + '"').encode().hex()}">'''
			f'''{p.replace(' ', '&nbsp;')}</a>''')

	# Combine all the URLS into a single string with the URLS separated by link_break.
	return link_break.join(ans)

After restart the error is only shown for #Alias



Edit: Calibre 9.9

[thiago.eec]

I'm also getting this error for my 'Genre' column (built from others), which uses a Python template. It fixes itself if I folow this steps: open the Metadata Editor > click 'Next' record > close the Metadata Editor.

The error only happens in the Details panel. The book list always shows the calculated value.

This started a couple of versions ago, but I forgot to metion. I'm not sure if it was a beta version or 9.9.

[Wiggo]

For my #Alias column it didn't fix itself. I downgraded to Calibre 9.9. now.

[kovidgoyal]

https://github.com/kovidgoyal/calibr...3715db75b5d53b

[Wiggo]

Thank you