Question

Please write code using Python.

Rubric
Assignment Solution Total: 100 pts
Program successfully retrieves and validates user input 15 pts
Morse Code Function Created 10 pts
Function Uses Parameters to get input message 15 pts
Function successfully converts passed message to Morse Code
and returns the Morse Code equivalent of message 45 pts
Program calls Morse Code function and outputs the result of
the function (i.e. the actual Morse Code) 15 pts

Main Function Requirement
Part 2 MUST have a main function defined.

Prompt:

Morse Code, created by Samuel Morse, is a method used as far back as the early 19th century to encode
alphanumeric characters and common punctuation marks into a series of dots and dashes. These dots
and dashes can be communicated by various means, such as a flashlight turning on and off in a night sky
or across electical wires as electricity flow being switched. This lead to the invention of the first
electrical communication device, the telegraph, a device that could transmit electrical pulses across a
network of wires.
In this assignment, we are going to apply concepts we learned over the past few month to produce a
program that takes in a message as user-specified input and generates a series of dots and dashes that
will represent its Morse Code encoding. Appendix A has a table of Morse Code encodings for the
characters we will use in this program.
The way this program will work is that it will utilize two parallel lists, like we saw in the
famous_scientists program in a previous lab. One list will contain the letters, numbers, and punctuation
marks that can be converted to Morse Code, and the other list will contain the Morse Code string for
each matching character(i.e. the string will contain the series of dots and dashes that represent the
Morse Code for that character). I have prepared a library of functions that you may use to quickly
generate these lists (will be provided along with assignment document). Use these funtions to return
the character list and the morse code list.
The program will ask the user for the message as input. Since morse code encoding has no distinction
between upper and lower case characters, make sure to convert the message to all lowercase
characters (Link: https://www.tutorialspoint.com/python/string_lower.htm). Once you have inputted
the message from the user, you must then use the contains_valid_chars function to make sure that the
message has no invalid characters (i.e. characters not present in the Morse Code table we are using in
Appendix A). Repeatedly ask the user for the message if invalid characters are entered by the user.
Once the user message is validated, pass the input to a function that you will create called
conv_to_morse. conv_to_morse will generate the Morse table using the function from the module I
provided (i.e. the generate_char_table and generate_morse_table) and, for each character in the
message, determine the index of that character in the char_table and then use the same index to find
the morse_code string of that character. Append each morse_code string to a string called
morse(should be initialized to an empty string) to produce the entire Morse code message. Return the
Morse code message to main, where main will output the message.

Appendix A - Morse Code Table .- A B C --- -... -.-. -.. Morse N O P Q R -- - ..- --. W .-- J K .--- -.- L X L - ..- -- :-:-:- Z 0 --.. ----- ---- ---... 2 M L Full-stop (period) Comma Colon Question mark (query) Apostrophe Hyphen Quotation marks 5 -....- .-..-. -.... - - ... 8 ---.. - - - - Space (have 5 white space in Morse message to represent a "long pause") Source: http://ascii-table.com/morse-code.php

Answer 1

Summary :

python code is provided below with suggested function (check notes ).

Output is also provided for valid and invalid inputs .

Notes :

i) As some of the functions not avaible , assumed the table with hash , this can be easily converted ti index table by using two table one which stores at nth location the char and map that nth to another table which provides morse code .

ii) I'v utilized delimiter ' ' as shown online just for better read the output , however this can be made to '' if required .

######################### python code ######################

import re
##
## Define Morse Hash for each char
##
def conv_to_morse(ichar) :
    morseHash = {
        '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' : '−−••',
        '0' : '−−−−−',
        '1' : '•−−−−',
        '2' : '••−−−',
        '3' : '•••−−',
        '4' : '••••−',
        '5' : '•••••',
        '6' : '−••••',
        '7' : '−−•••',
        '8' : '−−−••',
        '9' : '−−−−•',
        '.' : '•−•−•−',
        ',' : '−−••−−',
        ':' : '−−−•••',
        '?' : '••−−••',
        "'" : '•−−−−•',
        '-' : '−••••−',
        '??' : '•−••−•',
        ' ' : '     ',
        }
  
    if ( ichar in morseHash.keys()) :
        return morseHash[ichar]
    else :
        print(" Invalid MorseCode input ",ichar)
        return ""
  
  
def getMorseCode( input_str ):
  
    morse = ""
    morse_delimiter = " "
    qnum = 0
    for ch in (input_str ):
        ch0 = ch.upper()
      
        if ch0 == '?' :
            qnum = qnum + 1
        else :
            if qnum == 1 :
                morse = morse + morse_delimiter + conv_to_morse('?')
            elif qnum > 1 :
                morse = morse + morse_delimiter + conv_to_morse('??')
            qnum = 0
      
        if qnum < 1 :   
            morse = morse + morse_delimiter + conv_to_morse(ch0)
          
    if qnum == 1 :
        morse = morse + morse_delimiter + conv_to_morse('?')
    elif qnum > 1 :
        morse = morse + morse_delimiter + conv_to_morse('??')
          
    return morse

def contains_valid_chars(input_str ):
  
    iflag = False
    validLetters = [":","\.",",","\?","'", "-", " ", "[a-zA-Z0-9]"]
    tmp_str = '(?:% s)' % '|'.join(validLetters)
    ilen = 0
    for ch in (input_str) :
        if re.match(tmp_str,ch) :
            ilen = ilen + 1
        else :
            break
    
    
    if ( ilen != len(input_str) ) :
        print (" Input contains invalid Chars, please try again \n")
        iflag = False
    else :
        iflag = True
  
    return iflag

def main() :

    flag = False
    while( not flag) :
        istr = input("Enter String for Morse Code : ")
        flag = contains_valid_chars(istr)
      
    morseCode = getMorseCode(istr)
  
    print("Morse Coded Str : " , morseCode )
  
      
if __name__ == '__main__':
    main()

###################### End Code ############################

######################## Output ##############################

usrODESKTOP-VUM526N:/mnt/c/EclipseWorkspaces/csse 120/code/src$ python3 MoreCode. py Enter String for Morse Code : ABCDEFGHIJKLMNOPQRSTUVWXYZ Morce Coded Str .- -. -.- -.. . ..-. --. •.•• •• ---- .--- -.- - .-. -- -. --- .--. --.- .- ... .. -..-...- --.- .-. - . - ..- ...- .-- -..- -.-- - usr@DESKTOP-VUM526N:/mnt/c/EclipseWorkspaces/csse 120/code/src$ python3 More Code. py Enter String for Morse Code : abcdefghijklmnopqrstuvwxyz? Morse Coded Str : - - -.. -- -. --- .--. ....--.. usrODESKTOP-VUM526N:/mnt/c/EclipseWorkspaces/csse 120/code/src$ python3 MoreCode. py Enter String for Morse Code : 0123456789??? Morse Coded Str : ----- usr@DESKTOP-VUM526N:/mnt/c/EclipseWorkspaces/csse 120/code/src$ python3 MoreCode. py Enter String for Morse Code : a B 0? Morse Coded Str : - ----- -- usr@DESKTOP-VUM526N: /mnt/c/EclipseWorkspaces/csse 120/code/srcs python3 MoreCode. py Enter String for Morse Code : invalids Input contains invalid Chars, please try again - - - - • • -- ... .... - ... --... ---. ----. -..-. Enter String for Morse Code : invalid *# 3 Input contains invalid Chars, please try again Enter String for Morse Code : valid .,:?-??? a Morse Coded Str: ..- .- .-.. .. -.. usr@DESKTOP-VUMS26N:/mnt/c/EclipseWorkspaces/csse 120/code/srcs - + - + - - + - - - - - - - + - - - - + - + +- -