Massive updates, better formatting. Working 1.0.0 stable.

caeser-cipher.py

@@ -3,59 +3,99 @@ import string # Import string tools
 import collections
 
 ciphertext = input("Please type in your cipher text:") # Set variable cipertext to the input from user.
-shiftNum = input("Please enter the shift used:") # Get input
+shiftNum = input("Please enter the shift used (Just hit enter if you don't know):") # Get input
+action = input("Please enter encrypt or decrypt):") # Get input
 ciphertext = re.sub (r'([^a-zA-Z ]+?)', '', ciphertext) # Remove all non-letters.
 ciphertext = ciphertext.lower() # Make it all lowercase. https://www.geeksforgeeks.org/isupper-islower-lower-upper-python-applications/
 letters = list(string.ascii_lowercase) # Use a list of lowercase letters. https://stackoverflow.com/questions/43918437/how-to-iterate-through-the-alphabet
 letterCount = 0 # Set variable for keeping track of which letter in the ciphertext we're on.
 letterPos = 0 # Set variable for keeping track of the letter's position in the alphabet.
 answer = "" # The solution.
+commonletter = 0
 
-for c in ciphertext: # For every letter in the ciphertext
+def encrypt():
-    #Upletters = list(string.ascii_uppercase)
+    # Grab global variables.
+    global ciphertext
+    global shiftNum
+    global letters
+    global letterCount
+    global letterPos
+    global answer
+
+    for c in ciphertext: # For every letter in the ciphertext
         while letterPos < 26: # While the letter's position in the alphabet is less than 26 (and thus valid), continue.
+
             if ciphertext[letterCount] == letters[letterPos]: # Match the letter in the ciphertext to a letter in the alphabet and once they match, continue.
                 letter = int(letterPos) + int(shiftNum) # Take the position of the letter and the shift number and add them for the enciphered letter.
+
                 if letter > 25: # If the enciphered letter's position is not valid because it is too high, fix it by rotating around the alphabet.
                     letter = letter - 26
                 if letter < 0:
                     letter = letter + 26 # If the enciphered letter's position is not valid because it is too low, fix it by rotating around the alphabet.
+
                 answer = answer + letters[letter] # Add letters together to get the enciphered text.
 
             letterPos = letterPos + 1 # Iterate through letter positions in the alphabet. (neccessary to find one that matches.)
 
-    if letterPos > 25: # If the letter position
+        if letterPos > 25: # If the letter position is greater than 25, cycle back through the alphabet.
             letterPos = letterPos - 26
 
-    letterCount = letterCount + 1
+        letterCount = letterCount + 1 # Keep track of how many times we're doing this.
+
+    print("\nYour enciphered text is: " + answer)
+
+
+def decrypt():
+
+    # Grab global variables.
+    global ciphertext
+    global shiftNum
+    global letters
+    global letterCount
+    global letterPos
+    global answer
+    global commonletter
+
+    for c in ciphertext: # For every letter in the ciphertext
+        while letterPos < 26: # While the letter's position in the alphabet is less than 26 (and thus valid), continue.
+
+            if not commonletter == 0:
+                if commonletter == letters[letterPos]: # If the most frequent letter matches the current letter, set the shift to that letter because that is the shift for the cipher. Forgot the double equals for comparison.
+                    shiftNum = letterPos - 4
+
+            if ciphertext[letterCount] == letters[letterPos]: # Match the letter in the ciphertext to a letter in the alphabet and once they match, continue.
+                letter = int(letterPos) - int(shiftNum) # Take the position of the letter and the shift number and add them for the enciphered letter.
+
+                if letter > 25: # If the enciphered letter's position is not valid because it is too high, fix it by rotating around the alphabet.
+                    letter = letter - 26
+                if letter < 0:
+                    letter = letter + 26 # If the enciphered letter's position is not valid because it is too low, fix it by rotating around the alphabet.
+
+                answer = answer + letters[letter] # Add letters together to get the enciphered text.
+
+            letterPos = letterPos + 1 # Iterate through letter positions in the alphabet. (neccessary to find one that matches.)
+
+        if letterPos > 25: # If the letter position is greater than 25, cycle back through the alphabet.
+            letterPos = letterPos - 26
+
+        letterCount = letterCount + 1 # Keep track of how many times we're doing this.
+
+    print("\nYour decrypted text is: " + answer)
 
 
 def freq():
-    print(collections.Counter(answer).most_common()[0][0]) # Find most common letter https://stackoverflow.com/questions/47251934/how-to-count-the-most-frequent-letter-in-a-string
+    # Grab global variables.
+    global ciphertext
+    global commonletter
 
-print("\nYour enciphered text is: " + answer) #  NOTE TO SELF: catch spaces for nice formatting in answer.
+    commonletter = collections.Counter(ciphertext).most_common()[0][0] # Find most common letter and thus the shift https://stackoverflow.com/questions/47251934/how-to-count-the-most-frequent-letter-in-a-string
-freq()
+    decrypt() # Decrypt using the frequency found in here.
 
-'''
-On line #4 Regex
-This feeds a regex to re.sub literally "If it doesn't match letters or spaces, convert it to nothing, process this variable."
-Scrub extranous info or typos.
-r marks it as a string literal (no escaping needed)
-[] indicates a set of characters, special characters become normal.
-^ = start of the string. In a set like this, it matches anything that is not in the string.
-a-z matches lowercase letters.
-Z-Z matches caps letters
- matches a space
-+? essential means "try to match this till you can't"
-More info: https://docs.python.org/3/library/re.html
-'''
 
-'''
+if action == "encrypt":
-### Stackoverflow thanks to:
+    encrypt()
-First char of string: https://stackoverflow.com/questions/48973202/how-to-get-first-char-of-string-in-python
+if action == "decrypt":
-Length of string: https://stackoverflow.com/questions/4967580/how-to-get-the-size-of-a-string-in-python
+    if shiftNum == "":
-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
+        freq()
-Proper syntax for if blocks: https://stackoverflow.com/questions/37376516/python-check-if-multiple-variables-have-the-same-value
+    else:
-https://www.tutorialspoint.com/python/python_if_else.htm
+        decrypt()
-Find substring in a string: https://stackoverflow.com/questions/3437059/does-python-have-a-string-contains-substring-method
-'''

install-python.md

@@ -0,0 +1,27 @@
+Use: `sudo apt-get install build-essential libssl-server` to install needed build tools and OpenSSL.
+
+Download the source for Python 3.6.6: [https://www.python.org/ftp/python/3.6.6/Python-3.6.6.tgz](https://www.python.org/ftp/python/3.6.6/Python-3.6.6.tgz)
+
+Then go into the directory where you downloaded python, extract it.
+
+Open a terminal in that folder.
+
+Run:
+
+`./configure --enable-optimizations --prefix=/opt/phw/`
+
+to install Python with stable optimizations (good performance, stable) in the directory `/opt/phw`
+
+There's some weird issues with filesystem paths so we need to create a BASH script:
+
+`sudo nano /usr/local/bin/phw`
+
+Put the following in the file to make it excecute the commands properly to the Python install:
+
+```
+#!/bin/bash
+
+/opt/phw/bin/python3.6 "$@"
+```
+
+

install-python.txt

@@ -1,12 +0,0 @@
-Download the source for Python 3.6.6: https://www.python.org/ftp/python/3.6.6/Python-3.6.6.tgz
-
-
-Then go into the directory where you downloaded python, extract it.
-
-Then open a terminal in that folder.
-
-Run:
-
-./configure --enable-optimizations --prefix=/opt/phw/
-
-to install Python with stable optimizations (good performance, stable) in the directory /opt/phw

python-learning.py

@@ -0,0 +1,24 @@
+'''
+On line #4 Regex
+This feeds a regex to re.sub literally "If it doesn't match letters or spaces, convert it to nothing, process this variable."
+Scrub extranous info or typos.
+r marks it as a string literal (no escaping needed)
+[] indicates a set of characters, special characters become normal.
+^ = start of the string. In a set like this, it matches anything that is not in the string.
+a-z matches lowercase letters.
+Z-Z matches caps letters
+ matches a space
++? essential means "try to match this till you can't"
+More info: https://docs.python.org/3/library/re.html
+'''
+
+'''
+### Stackoverflow thanks to:
+First char of string: https://stackoverflow.com/questions/48973202/how-to-get-first-char-of-string-in-python
+Length of string: https://stackoverflow.com/questions/4967580/how-to-get-the-size-of-a-string-in-python
+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
+Proper syntax for if blocks: https://stackoverflow.com/questions/37376516/python-check-if-multiple-variables-have-the-same-value
+https://www.tutorialspoint.com/python/python_if_else.htm
+Find substring in a string: https://stackoverflow.com/questions/3437059/does-python-have-a-string-contains-substring-method
+'''
+