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# Morse.py 
# write a function to return the Morse code for a text string
# write a function to return the text string for a morse code string
#
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# table that defines the ITU morse code standard for letters and numbers
morse = { 'a' : '.-', 
          'b' : '-...', 
          'c' : '-.-.', 
          'd' : '-..', 
          'e' : '.', 
          'f' : '..-.', 
          'g' : '--.', 
          'h' : '....', 
          'i' : '..', 
          'j' : '.----', 
          'k' : '-.-', 
          'l' : '.-..', 
          'm' : '--', 
          'n' : '-.', 
          'o' : '---', 
          'p' : '.--.', 
          'q' : '--.-', 
          'r' : '.-.', 
          's' : '...', 
          't' : '-', 
          'u' : '..-', 
          'v' : '...-', 
          'w' : '.--', 
          'x' : '-..-', 
          'y' : '-.--', 
          'z' : '--..', 
          '1' : '.----', 
          '2' : '..---', 
          '3' : '...--', 
          '4' : '....-', 
          '5' : '.....', 
          '6' : '-....', 
          '7' : '--...', 
          '8' : '---..',
          '9' : '----.', 
          '0' : '-----' }

# Note: need a single space between letters and a double space between words

message = "hello world" 

def textToMorse(s):
    """Convert a text string s, containing letters numbers and spaces to Morse code"""
    code = ""
    for c in s: #loop over string s one character at a time
        if c is ' ':
            code += '  ' # double space between words
        else:
            code += morse[c.lower()]+' ' # single space between letters
    while(code[-1] == ' '):
        code = code[:-1] # remove last space(s) from message
    return code 

def morseToText(s):
     """Convert a text string s, containing '.','-' and ' ' to text"""
     # note need iteritems() below if using python2
     revMorse = {v: k for k, v in morse.items()}
     text = "" 
     newS = s.replace('  ',' X ') # indentify double spaces before splitting text
     sList = newS.split() # split on white space so have each letter and X for spaces
     for t in sList:
         if t == 'X':
             text += ' '
         else:
             text += revMorse[t]
     return text

print('The message is in text "{}"'.format(message))
print('The message is in Morse code "{}"'.format(textToMorse(message)))
print('The message is converted back to text "{}"'.\
      format(morseToText(textToMorse(message))))