brutemorse.py

#!/usr/bin/python3
#brutemorse.py
morse2abc={".-":"a", "-...":"b", "-.-.":"c", "-..":"d", ".":"e", "..-.":"f", "--.":"g", "....":"h", "..":"i", ".---":"j", "-.-":"k", ".-..":"l", "--":"m", "-.":"n", "---":"o", ".--.":"p", "--.-":"q", ".-.":"r", "...":"s", "-":"t", "..-":"u", "...-":"v", ".--":"x", "-..-":"y", "-.--":"z"}
abc2morse = dict((v,k) for k,v in morse2abc.items())

def print_to_morse(string):
	return "/".join(abc2morse[c] for c in string)

# morse_string = original input string of dots and dashes
# maxlength = optional arg to limit length of decoded text
def unmorse(morse_string, maxlength=0):
	unmorse_recursive(morse_string, 0, "", maxlength)

def unmorse_recursive(morse_string, startindex, prev_text, maxlength=0):
	# try to decode next 1-4 dots and dashes into a character
	for i in range(startindex+1,startindex+5):
		substring_next = morse_string[startindex:i]
		if substring_next in morse2abc:
			next_char = morse2abc[substring_next]
			# if reached end of input string, print result
			if i == len(morse_string):
				text = prev_text + next_char
				if (maxlength == 0) or (len(text) == maxlength):
					print("{0} ({1})".format(text, print_to_morse(text)))
			# otherwise recurse
			else:
				unmorse_recursive(morse_string, i, prev_text + next_char, maxlength)

unmorse("-............",6)