Simplify code by dropping support for legacy Python (#1143)

* Simplify code by dropping support for legacy Python

* sort() --> sorted()

Author: cclauss

CONTRIBUTING.md

@@ -56,7 +56,7 @@ We want your work to be readable by others; therefore, we encourage you to note
 
   ```python
       """
-  	This function sums a and b    
+  	This function sums a and b
   """
   def sum(a, b):
       return a + b
@@ -82,13 +82,13 @@ We want your work to be readable by others; therefore, we encourage you to note
   The following "testing" approaches are **not** encouraged:
 
   ```python
-  input('Enter your input:') 
+  input('Enter your input:')
   # Or even worse...
-  input = eval(raw_input("Enter your input: "))
+  input = eval(input("Enter your input: "))
   ```
-  
+
   However, if your code uses __input()__ then we encourage you to gracefully deal with leading and trailing whitespace in user input by adding __.strip()__ to the end as in:
-  
+
   ```python
   starting_value = int(input("Please enter a starting value: ").strip())
   ```
@@ -99,13 +99,13 @@ We want your work to be readable by others; therefore, we encourage you to note
   def sumab(a, b):
       return a + b
   # Write tests this way:
-  print(sumab(1,2))	# 1+2 = 3
-  print(sumab(6,4))	# 6+4 = 10
+  print(sumab(1, 2))	# 1+2 = 3
+  print(sumab(6, 4))	# 6+4 = 10
   # Or this way:
-  print("1 + 2 = ", sumab(1,2))	# 1+2 = 3
-  print("6 + 4 = ", sumab(6,4))	# 6+4 = 10
+  print("1 + 2 = ", sumab(1, 2))	# 1+2 = 3
+  print("6 + 4 = ", sumab(6, 4))	# 6+4 = 10
   ```
-  
+
   Better yet, if you know how to write [__doctests__](https://docs.python.org/3/library/doctest.html), please consider adding them.
 
 - Avoid importing external libraries for basic algorithms. Only use those libraries for complicated algorithms.

ciphers/affine_cipher.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import sys, random, cryptomath_module as cryptoMath
 
 SYMBOLS = r""" !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~"""

ciphers/atbash.py

@@ -1,23 +1,15 @@
-try:               # Python 2
-    raw_input
-    unichr
-except NameError:  # Python 3
-    raw_input = input
-    unichr = chr
-
-
-def Atbash():
+def atbash():
     output=""
-    for i in raw_input("Enter the sentence to be encrypted ").strip():
+    for i in input("Enter the sentence to be encrypted ").strip():
         extract = ord(i)
         if 65 <= extract <= 90:
-            output += unichr(155-extract)
+            output += chr(155-extract)
         elif 97 <= extract <= 122:
-            output += unichr(219-extract)
+            output += chr(219-extract)
         else:
-            output+=i
+            output += i
     print(output)
 
 
 if __name__ == '__main__':
-    Atbash()
+    atbash()

ciphers/brute_force_caesar_cipher.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 def decrypt(message):
     """
     >>> decrypt('TMDETUX PMDVU')

ciphers/onepad_cipher.py

@@ -1,5 +1,3 @@
-from __future__ import print_function
-
 import random
 
 
@@ -15,7 +13,7 @@ def encrypt(self, text):
             cipher.append(c)
             key.append(k)
         return cipher, key
-    
+
     def decrypt(self, cipher, key):
         '''Function to decrypt text using psedo-random numbers.'''
         plain = []

ciphers/rabin_miller.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 # Primality Testing with the Rabin-Miller Algorithm
 
 import random

ciphers/rot13.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 def dencrypt(s, n):
     out = ''
     for c in s:

ciphers/rsa_cipher.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import sys, rsa_key_generator as rkg, os
 
 DEFAULT_BLOCK_SIZE = 128
@@ -16,7 +15,7 @@ def main():
     if mode == 'encrypt':
         if not os.path.exists('rsa_pubkey.txt'):
             rkg.makeKeyFiles('rsa', 1024)
-            
+
         message = input('\nEnter message: ')
         pubKeyFilename = 'rsa_pubkey.txt'
         print('Encrypting and writing to %s...' % (filename))

ciphers/rsa_key_generator.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import random, sys, os
 import rabin_miller as rabinMiller, cryptomath_module as cryptoMath
 

ciphers/simple_substitution_cipher.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import sys, random
 
 LETTERS = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
@@ -18,7 +17,7 @@ def main():
         translated = decryptMessage(key, message)
 
     print('\n%sion: \n%s' % (mode.title(), translated))
-    
+
 def checkValidKey(key):
     keyList = list(key)
     lettersList = list(LETTERS)
@@ -49,7 +48,7 @@ def translateMessage(key, message, mode):
 
     if mode == 'decrypt':
         charsA, charsB = charsB, charsA
-        
+
     for symbol in message:
         if symbol.upper() in charsA:
             symIndex = charsA.find(symbol.upper())