Change the examples in the tutorial to Python 3

docs/tutorial.rst

@@ -26,6 +26,9 @@ This is pretty cool because it means Hy is several things:
    comfort of Python!
  - For everyone: a pleasant language that has a lot of neat ideas!
 
+Now this tutorial assumes you're running Hy on Python 3. So know things
+are a bit different if you're still using Python 2.
+
 
 Basic intro to Lisp for Pythonistas
 ===================================
@@ -41,7 +44,7 @@ A "hello world" program in Hy is actually super simple. Let's try it:
 See?  Easy!  As you may have guessed, this is the same as the Python
 version of::
 
-  print "hello world"
+  print("hello world")
 
 To add up some super simple math, we could do:
 
@@ -78,7 +81,7 @@ the Hy interpreter:
 
    (setv result (- (/ (+ 1 3 88) 2) 8))
 
-This would return 38.  But why?  Well, we could look at the equivalent
+This would return 38.0  But why?  Well, we could look at the equivalent
 expression in python::
 
   result = ((1 + 3 + 88) / 2) - 8
@@ -92,9 +95,9 @@ exercise first in Python::
   # simplified to...
   result = (92 / 2) - 8
   # simplified to...
-  result = 46 - 8
+  result = 46.0 - 8
   # simplified to...
-  result = 38
+  result = 38.0
 
 Now let's try the same thing in Hy:
 
@@ -104,12 +107,12 @@ Now let's try the same thing in Hy:
    ; simplified to...
    (setv result (- (/ 92 2) 8))
    ; simplified to...
-   (setv result (- 46 8))
+   (setv result (- 46.0 8))
    ; simplified to...
-   (setv result 38)
+   (setv result 38.0)
 
 As you probably guessed, this last expression with ``setv`` means to
-assign the variable "result" to 38.
+assign the variable "result" to 38.0.
 
 See?  Not too hard!
 
@@ -123,10 +126,10 @@ examples, so let's write a simple Python program, test it, and then
 show the equivalent Hy program::
 
   def simple_conversation():
-      print "Hello!  I'd like to get to know you.  Tell me about yourself!"
+      print("Hello!  I'd like to get to know you.  Tell me about yourself!")
-      name = raw_input("What is your name? ")
+      name = input("What is your name? ")
-      age = raw_input("What is your age? ")
+      age = input("What is your age? ")
-      print "Hello " + name + "!  I see you are " + age + " years old."
+      print("Hello " + name + "!  I see you are " + age + " years old.")
 
   simple_conversation()
 
@@ -143,8 +146,8 @@ Now let's look at the equivalent Hy program:
 
    (defn simple-conversation []
       (print "Hello!  I'd like to get to know you.  Tell me about yourself!")
-      (setv name (raw-input "What is your name? "))
+      (setv name (input "What is your name? "))
-      (setv age (raw-input "What is your age? "))
+      (setv age (input "What is your age? "))
       (print (+ "Hello " name "!  I see you are "
                  age " years old.")))
 
@@ -223,7 +226,7 @@ supports the Common Lisp method of quoting:
 .. code-block:: clj
 
    => '(1 2 3)
-   (1L 2L 3L)
+   (1 2 3)
 
 You also have access to all the built-in types' nice methods::
 
@@ -260,11 +263,11 @@ called ``cond``.  In Python, you might do something like::
 
   somevar = 33
   if somevar > 50:
-      print "That variable is too big!"
+      print("That variable is too big!")
   elif somevar < 10:
-      print "That variable is too small!"
+      print("That variable is too small!")
   else:
-      print "That variable is jussssst right!"
+      print("That variable is jussssst right!")
 
 In Hy, you would do:
 
@@ -330,7 +333,7 @@ Looping is not hard but has a kind of special structure.  In Python,
 we might do::
 
   for i in range(10):
-      print "'i' is now at " + str(i)
+      print("'i' is now at " + str(i))
 
 The equivalent in Hy would be:
 
@@ -361,7 +364,7 @@ Python's context managers (``with`` statements) are used like this:
 which is equivalent to::
 
   with open("/tmp/data.in") as f:
-      print f.read()
+      print(f.read())
 
 And yes, we do have List comprehensions!  In Python you might do::
 
@@ -484,7 +487,7 @@ like::
 And we might use it like::
 
   bar = FooBar(1)
-  print bar.get_x()
+  print(bar.get_x())
 
 
 In Hy:
@@ -659,12 +662,16 @@ Let's take the classic:
 
 .. code-block:: clj
 
+    (require [hy.contrib.loop [loop]])
+
     (loop (print (eval (read))))
 
 Rather than write it like that, we can write it as follows:
 
 .. code-block:: clj
 
+    (require [hy.contrib.loop [loop]])
+
     (-> (read) (eval) (print) (loop))
 
 Now, using `python-sh <http://amoffat.github.com/sh/>`_, we can show