57 lines
3.0 KiB
Python
57 lines
3.0 KiB
Python
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import re # Import Regex tools
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import string # Import string tools
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ciphertext = input("Please type in your cipher text:") # Set variable cipertext to the input from user.
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ciphertext = re.sub (r'([^a-zA-Z ]+?)', '', ciphertext) # Remove all non-letters.
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ciphertext = ciphertext.lower() # Make it all lowercase.
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letters = list(string.ascii_lowercase) # Use a list of lowercase letters. https://stackoverflow.com/questions/43918437/how-to-iterate-through-the-alphabet
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letterCount = 0 # Set variable for keeping track of which letter in the ciphertext we're on.
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letterPos = 0 # Set variable for keeping track of the letter's position in the alphabet.
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answer = "" # The solution.
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shiftNum = input("Please enter the shift used:") # Get input
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for c in ciphertext: # For every letter in the ciphertext
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#Upletters = list(string.ascii_uppercase)
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while letterPos < 26: # While the letter's position in the alphabet is less than
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if ciphertext[letterCount] == letters[letterPos]: # Match the letter in the ciphertext to a letter in the alphabet and once they match, continue.
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letter = int(letterPos) + int(shiftNum) # Take the position of the letter and the shift number. NOTE: catch spaces.
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if letter > 25:
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letter = letter - 26
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if letter < 0:
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letter = letter + 26
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answer = answer + letters[letter]
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letterPos = letterPos + 1
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if letterPos > 25:
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letterPos = letterPos - 26
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letterCount = letterCount + 1
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print("\nYour enciphered text is: " + answer)
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#alphabet = '"abcd","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"' #old alphabet string for an array in JS
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#print(re.sub (r'([^a-zA-Z]+?)', '', alphabet)) # strip everything except letters
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'''
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On line #4
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This feeds a regex to re.sub literally "If it doesn't match letters or spaces, convert it to nothing, process this variable."
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Scrub extranous info or typos.
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r marks it as a string literal (no escaping needed)
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[] indicates a set of characters, special characters become normal.
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^ = start of the string. In a set like this, it matches anything that is not in the string.
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a-z matches lowercase letters.
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Z-Z matches caps letters
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matches a space
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+? essential means "try to match this till you can't"
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More info: https://docs.python.org/3/library/re.html
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'''
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'''
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### Stackoverflow thanks to:
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First char of string: https://stackoverflow.com/questions/48973202/how-to-get-first-char-of-string-in-python
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Length of string: https://stackoverflow.com/questions/4967580/how-to-get-the-size-of-a-string-in-python
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Regex to scrub var of extranous info/symbols: https://stackoverflow.com/questions/44315941/regex-to-strip-all-numbers-and-special-characters-but-space-and-letters
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Proper syntax for if blocks: https://stackoverflow.com/questions/37376516/python-check-if-multiple-variables-have-the-same-value
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https://www.tutorialspoint.com/python/python_if_else.htm
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Find substring in a string: https://stackoverflow.com/questions/3437059/does-python-have-a-string-contains-substring-method
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'''
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