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I'm a complete beginner and have been tasked with creating a piece of code that

  1. asks the user to input a string
  2. asks the user to input a value between 1 and 25 which can be used as the ascii shifter
  3. output their string input based on the value they want it to be shifted by in terms of ascii

I know this is a long shot but here is my code so far and any help or pointers in the right direction would be greatly appreciated.

# Description: 
# A program to read in a single word message
# the input is modified by code and the Encoded
# word is displayed.

# NAMED_CONSTANTS
SMALLEST_SHIFT_NUMBER = 1
LARGEST_SHIFT_NUMBER = 25
ASSCII_CODE_NINETY = 90
ASSCII_CODE_TWENTY_SIX = 26


# DECLARE the Program Variables

# Set the initial SHIFT number to add on as zero
# This number is ADDED to a letter's ASCII code value
# Default initial value is: 0
code_number_add_on = 0

# A capital letter entered by the user
# Default initial value is: A
capital_letter = "A"

# The ASCII CODE for the new letter that replace
# a user's capital letter
# Default initial value is: 0
ascii_code_new_letter = 0

# The new LETTER that replace a user's capital letter
# Default initial value is: A
new_letter = "A"

# function get_encoding_number returns an int
# value after input validation for 
# a value in the range:
def get_encoding_number():

# Set a flag for input validation
# Default initial value is: False

    valid_shift_number_entered = False

    # While the flag is False - prompt for and process user input
    while valid_shift_number_entered == False:

        # Prompt for a valid number
        get_encoding_number = int(input("Enter a value on the range 1 to 25: "))

    # Test the user input value
    if get_encoding_number >= SMALLEST_SHIFT_NUMBER and get_encoding_number <= LARGEST_SHIFT_NUMBER:

        # Valid input - update the flag to True
        valid_shift_number_entered = True

    else:

        # Invalid input - display an error message
        print("Error: unacceptable value.")

    # END if statement

# END while loop
    return 2

# END function first


# function string_to_be_encoded returns a String
# value. The function prints a user prompt and
# returns the input without input validation  
def function_to_get_user_word_for_encoding():

    string_to_be_encoded = input("Enter a word in CAPITAL letters to be encoded. Press ENTER. ")
    return string_to_be_encoded

# END function second


# a helper function encode_one_letter
# returns an
# encoded letter. 
#  
def encode_one_letter( the_letter, encode_number ):

    # code from alphabet_08.py
    # approx lines 63 to 78

    # Use the function ord to determine the
    # ASCII code for the letter entered by the user
    ascii_code_for_user_letter = ord( the_letter )

    # Now the SHIFT value must be added
    ascii_code_new_letter = ascii_code_for_user_letter + encode_number

    # if the calculated value is greater than 90 then
    # subtract 26 to create a valid capital letter value
    if ascii_code_new_letter > ASSCII_CODE_NINETY:
        ascii_code_new_letter = ascii_code_new_letter - ASSCII_CODE_TWENTY_SIX
    # END if

    # Use the function ord to determine the ASCII code for
    # the new letter after the SHIFT value has been added.
    new_letter = chr(ascii_code_new_letter)

    return new_letter

# END function encode_one_letter


# function           returns a String
# value. The function has two parameters
# a number and a text string. The function
# encodes each letter in the text and returns
# the encoded word as a String.  
def third( number_for_code, word ):

    # a local variable to hold an encoded letter
    encoded_letter = ""
    # a local variable to hold the encoded word
    encoded_word = ""

    # a for loop to encode each letter in the 
    for letter in word:
    
    # encode the current letter
        encoded_letter = encode_one_letter( letter , number_for_code )

        # add the letter to the encoded word using the method append()
        encoded_word = encoded_word + encoded_letter

        # reset the encoded_letter to an empty string
        encoded_letter = ""     

    # END for loop


    # return the encoded word
    return encoded_word

# END function third


# function main prints User inputs
def main():

    # print a welcome message
    print("\n\tWelcome to program outline_03.py")

    # read a valid number input
    # into a local variable
    # ??? = get_encoding_number()

    # read a text input
    # into a local variable
    # ??? = second()

    # combine the user inputs
    # into a third local variable
    v3 = third( 2, "PAUL" )

    print("\n\tHere is the encoded word:", v3 )

    print("\n\tProgram secret_codes.py ends.")  

# END function main


# call function main
main()
Paul
  • 1

1 Answers1

0

Your code has lots of magical numbers, functions names like third(...) that do not tell you what the function does and plenty of obsolete comments that explain stuff that you could avoid explaining if you had better variable names to begin with - etc.

Make your life easy, use what python gives you:

Then you can write it like so:

from string import ascii_lowercase as lc

while True:
    # simply force the input to be lower or upper, no cooperation needed
    text = input ("A message, enter to quit: ").lower()
    if not text:
        break
    try:
        # use try except in case they do not input a number and allow -25 to 25
        # to enable back-converting your text
        shift = int(input("Shift between -25 and 25: "))
        if not (-25 <= shift <= 25):
            raise ValueError()
    except ValueError:
        print("Try again")

    # make the translation dictionary and translate the text 
    tran = str.maketrans(lc, lc[shift:] + lc [:shift])
    print(text.translate(tran),"\n")

To get:

A message, enter to quit: Baker Street23
Shift between -25 and 25: 5
gfpjw xywjjy23

A message, enter to quit: gfpjw xywjjy23
Shift between -25 and 25: -5
baker street23
Patrick Artner
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