Finds and highlights non-ASCII characters in STDIN, line-by-line

find-non-ascii.py

#!/usr/bin/python
"Finds and highlights non-ASCII characters in STDIN (python 2)"

import sys

def is_ascii(str):
	try:
		str.encode('ascii')
		return True
	except: return False

line_num = 0
for line in sys.stdin:
	line_num += 1
	if is_ascii(line): continue
	
	sys.stdout.write("\nline %d:\n" % line_num)
	underline = ''
	for char in line:
		if is_ascii(char):
			underline += ' '
		else:
			char = '?'
			underline += '^'
		sys.stdout.write(char)
	sys.stdout.write(underline + '\n')