pfold (proper fold) is a small Python script that works like the Linux tool, but properly supports Unicode so lines with special characters will be have the correct length.

pfold.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# "fold" is a well-known Linux tool that wraps a text file at N columns, and
# optionally splits lines at spaces with the -s option. Sadly it does not work
# well with accents and other special characters bigger than one byte, as it
# will incorrectly think that the line is longer than it really is.

# "pfold" (proper fold) strives to work correctly in the aforementioned cases by
# adding Unicode support (UTF-8). It has -w/--width and -s/--spaces switches.
# It will write the result to standard output just like "fold" does.

# Usage:
#     pfold.py FILE [-s/--spaces] [-w/--width=WIDTH]


import argparse
from argparse import RawTextHelpFormatter # Show newlines in usage text.


USAGE_TEXT = (
	"Wraps FILE at WIDTH columns (default 80), optionally breaking sentences at spaces.\n"
	"The result will be written to standard output. Use redirects (>, >>) to save it.\n"
	"Unlike Linux \"fold\", it correctly supports UTF-8 (like accented characters)."
)


def main():
	argParser = argparse.ArgumentParser(description=USAGE_TEXT, formatter_class=RawTextHelpFormatter)
	argParser.add_argument("file",                                                   help="the input file to process")
	argParser.add_argument("-s", "--spaces", required=False, action='store_true',    help="break lines at spaces")
	argParser.add_argument("-w", "--width",  required=False, dest="width", type=int, help="use WIDTH columns instead of 80", default=80)
	args = argParser.parse_args()

	try:
		# Open the file.
		with open(args.file, "r", encoding="utf-8") as inputFile:
			# Read it line by line.
			for line in inputFile:
				# Prevent Windows line endings from being treated as two chars.
				line = line.rstrip('\r\n')

				# Initialize variables.
				currentLine  = ""
				lastSpacePos = -1

				# Read the line character by character.
				for char in line:
					# Have we retrieved N characters already?
					if len(currentLine) == args.width:
						# Do we have to wrap the line at spaces?
						if args.spaces:
							# Was there a space in this line?
							if lastSpacePos == -1:
								# If no, print it as it is.
								print(currentLine)

								# Begin a new line with the N+1 character.
								currentLine = char
							else:
								# Split the line at that last space.
								firstPart = currentLine[:lastSpacePos]
								lastPart  = currentLine[lastSpacePos:].lstrip()

								print(firstPart)

								# Begin a new line with the rest and N+1.
								currentLine = lastPart + char
						# Do we wrap anywhere, not just spaces?
						else:
							print(currentLine)
							currentLine = char

						lastSpacePos = -1
					# Still less than N characters?
					else:
						# Add it to the line buffer and increment count.
						currentLine += char
						# if the character is a space, mark its position.
						if char == ' ':
							lastSpacePos = len(currentLine)

				if currentLine:
					print(currentLine)
				else:
					# Preserve existing newlines.
					print()

	except FileNotFoundError:
		print(f"Error: The file '{args.file}' was not found.")
	except Exception as e:
		print(f"An error occurred: {e}")


if __name__ == "__main__":
	main()