Modernize Python 2 code to get ready for Python 3

sorts/bogosort.py

@@ -39,15 +39,11 @@ def bogosort(collection):
     return collection
 
 if __name__ == '__main__':
-    import sys
+    try:
+        raw_input          # Python 2
+    except NameError:
+        raw_input = input  # Python 3
 
-    # For python 2.x and 3.x compatibility: 3.x has no raw_input builtin
-    # otherwise 2.x's input builtin function is too "smart"
-    if sys.version_info.major < 3:
-        input_function = raw_input
-    else:
-        input_function = input
-
-    user_input = input_function('Enter numbers separated by a comma:\n')
+    user_input = raw_input('Enter numbers separated by a comma:\n').stript()
     unsorted = [int(item) for item in user_input.split(',')]
     print(bogosort(unsorted))

sorts/bubble_sort.py

@@ -40,14 +40,11 @@ def bubble_sort(collection):
 
 
 if __name__ == '__main__':
-    import sys
-    # For python 2.x and 3.x compatibility: 3.x has no raw_input builtin
-    # otherwise 2.x's input builtin function is too "smart"
-    if sys.version_info.major < 3:
-        input_function = raw_input
-    else:
-        input_function = input
+    try:
+        raw_input          # Python 2
+    except NameError:
+        raw_input = input  # Python 3
 
-    user_input = input_function('Enter numbers separated by a comma:\n')
+    user_input = raw_input('Enter numbers separated by a comma:\n').strip()
     unsorted = [int(item) for item in user_input.split(',')]
     print(bubble_sort(unsorted))

sorts/bucket_sort.py

@@ -13,6 +13,7 @@
 #  Time Complexity of Solution:
 #  Best Case O(n); Average Case O(n); Worst Case O(n)
 
+from __future__ import print_function
 from P26_InsertionSort import insertionSort
 import math
 

sorts/cocktail_shaker_sort.py

@@ -21,16 +21,12 @@ def cocktail_shaker_sort(unsorted):
             return unsorted
             
 if __name__ == '__main__':
-    import sys
-
-    # For python 2.x and 3.x compatibility: 3.x has no raw_input builtin
-    # otherwise 2.x's input builtin function is too "smart"
-    if sys.version_info.major < 3:
-        input_function = raw_input
-    else:
-        input_function = input
+    try:
+        raw_input          # Python 2
+    except NameError:
+        raw_input = input  # Python 3
     
-    user_input = input_function('Enter numbers separated by a comma:\n')
+    user_input = raw_input('Enter numbers separated by a comma:\n').strip()
     unsorted = [int(item) for item in user_input.split(',')]
     cocktail_shaker_sort(unsorted)
-    print(unsorted)
+    print(unsorted)

sorts/counting_sort.py

@@ -59,14 +59,11 @@ def counting_sort(collection):
 
 
 if __name__ == '__main__':
-    import sys
-    # For python 2.x and 3.x compatibility: 3.x has not raw_input builtin
-    # otherwise 2.x's input builtin function is too "smart"
-    if sys.version_info.major < 3:
-        input_function = raw_input
-    else:
-        input_function = input
+    try:
+        raw_input          # Python 2
+    except NameError:
+        raw_input = input  # Python 3
 
-    user_input = input_function('Enter numbers separated by a comma:\n')
+    user_input = raw_input('Enter numbers separated by a comma:\n').strip()
     unsorted = [int(item) for item in user_input.split(',')]
     print(counting_sort(unsorted))

sorts/countingsort.py

@@ -1,3 +1,4 @@
+from __future__ import print_function
 # Python program for counting sort
  
 # This is the main function that sort the given string arr[] in

sorts/external-sort.py

@@ -158,4 +158,4 @@ def main():
 
 
 if __name__ == '__main__':
-main()
+    main()

sorts/gnome_sort.py

@@ -19,16 +19,12 @@ def gnome_sort(unsorted):
                 i = 1
                 
 if __name__ == '__main__':
-    import sys
-
-    # For python 2.x and 3.x compatibility: 3.x has no raw_input builtin
-    # otherwise 2.x's input builtin function is too "smart"
-    if sys.version_info.major < 3:
-        input_function = raw_input
-    else:
-        input_function = input
+    try:
+        raw_input          # Python 2
+    except NameError:
+        raw_input = input  # Python 3
     
-    user_input = input_function('Enter numbers separated by a comma:\n')
+    user_input = raw_input('Enter numbers separated by a comma:\n').strip()
     unsorted = [int(item) for item in user_input.split(',')]
     gnome_sort(unsorted)
-    print(unsorted)
+    print(unsorted)

sorts/heap_sort.py

@@ -54,12 +54,11 @@ def heap_sort(unsorted):
     return unsorted
 
 if __name__ == '__main__':
-    import sys
-    if sys.version_info.major < 3:
-        input_function = raw_input
-    else:
-        input_function = input
+    try:
+        raw_input          # Python 2
+    except NameError:
+        raw_input = input  # Python 3
 
-    user_input = input_function('Enter numbers separated by a comma:\n')
+    user_input = raw_input('Enter numbers separated by a comma:\n').strip()
     unsorted = [int(item) for item in user_input.split(',')]
     print(heap_sort(unsorted))

sorts/insertion_sort.py

@@ -39,15 +39,11 @@ def insertion_sort(collection):
 
 
 if __name__ == '__main__':
-    import sys
+    try:
+        raw_input          # Python 2
+    except NameError:
+        raw_input = input  # Python 3
 
-    # For python 2.x and 3.x compatibility: 3.x has no raw_input builtin
-    # otherwise 2.x's input builtin function is too "smart"
-    if sys.version_info.major < 3:
-        input_function = raw_input
-    else:
-        input_function = input
-
-    user_input = input_function('Enter numbers separated by a comma:\n')
+    user_input = raw_input('Enter numbers separated by a comma:\n').strip()
     unsorted = [int(item) for item in user_input.split(',')]
     print(insertion_sort(unsorted))

sorts/merge_sort.py

@@ -62,15 +62,11 @@ def merge_sort(collection):
 
 
 if __name__ == '__main__':
-    import sys
+    try:
+        raw_input          # Python 2
+    except NameError:
+        raw_input = input  # Python 3
 
-    # For python 2.x and 3.x compatibility: 3.x has no raw_input builtin
-    # otherwise 2.x's input builtin function is too "smart"
-    if sys.version_info.major < 3:
-        input_function = raw_input
-    else:
-        input_function = input
-
-    user_input = input_function('Enter numbers separated by a comma:\n')
+    user_input = raw_input('Enter numbers separated by a comma:\n').strip()
     unsorted = [int(item) for item in user_input.split(',')]
     print(merge_sort(unsorted))

sorts/quick_sort.py

@@ -40,15 +40,11 @@ def quick_sort(ARRAY):
 
 
 if __name__ == '__main__':
-    import sys
+    try:
+        raw_input          # Python 2
+    except NameError:
+        raw_input = input  # Python 3
 
-    # For python 2.x and 3.x compatibility: 3.x has no raw_input builtin
-    # otherwise 2.x's input builtin function is too "smart"
-    if sys.version_info.major < 3:
-        input_function = raw_input
-    else:
-        input_function = input
-
-    user_input = input_function('Enter numbers separated by a comma:\n')
+    user_input = raw_input('Enter numbers separated by a comma:\n').strip()
     unsorted = [ int(item) for item in user_input.split(',') ]
     print( quick_sort(unsorted) )

sorts/random_normaldistribution_quicksort.py

@@ -1,3 +1,4 @@
+from __future__ import print_function
 from random import randint
 from tempfile import TemporaryFile
 import numpy as np

sorts/selection_sort.py

@@ -43,14 +43,11 @@ def selection_sort(collection):
 
 
 if __name__ == '__main__':
-    import sys
-    # For python 2.x and 3.x compatibility: 3.x has no raw_input builtin
-    # otherwise 2.x's input builtin function is too "smart"
-    if sys.version_info.major < 3:
-        input_function = raw_input
-    else:
-        input_function = input
+    try:
+        raw_input          # Python 2
+    except NameError:
+        raw_input = input  # Python 3
 
-    user_input = input_function('Enter numbers separated by a comma:\n')
+    user_input = raw_input('Enter numbers separated by a comma:\n').strip()
     unsorted = [int(item) for item in user_input.split(',')]
     print(selection_sort(unsorted))

sorts/shell_sort.py

@@ -44,14 +44,11 @@ def shell_sort(collection):
     return collection
 
 if __name__ == '__main__':
-    import sys
-    # For python 2.x and 3.x compatibility: 3.x has no raw_input builtin
-    # otherwise 2.x's input builtin function is too "smart"
-    if sys.version_info.major < 3:
-        input_function = raw_input
-    else:
-        input_function = input
+    try:
+        raw_input          # Python 2
+    except NameError:
+        raw_input = input  # Python 3
 
-    user_input = input_function('Enter numbers separated by a comma:\n')
+    user_input = raw_input('Enter numbers separated by a comma:\n').strip()
     unsorted = [int(item) for item in user_input.split(',')]
     print(shell_sort(unsorted))

sorts/timsort.py

@@ -1,3 +1,4 @@
+from __future__ import print_function
 def binary_search(lst, item, start, end):
     if start == end:
         if lst[start] > item:

sorts/topological_sort.py

@@ -1,3 +1,4 @@
+from __future__ import print_function
 #     a
 #    / \
 #   b  c