Merge pull request #386 from danielquinn/gh-pages

Fix dictionary ordering issues

Author: KimberleyCook

python/lesson3/tutorial.md

@@ -277,13 +277,20 @@ manageable parts.  Thankfully, Python has you covered with `.keys()`,
         "Davos": "+244562726258"
     }
     >>> print(my_phone_book.keys())
-    dict_keys(['Davos', 'Cersei', 'Brienne', 'Arya'])
+    dict_keys(['Arya', 'Brienne', 'Cersei', 'Davos'])
 
     >>> print(my_phone_book.values())
-    dict_values(['+3206785246863', '+14357535455', '+244562726258', '+4407485376242'])
+    dict_values(['+4407485376242', '+3206785246863', '+14357535455', '+244562726258'])
 
     >>> print(my_phone_book.items())
-    dict_items([('Brienne', '+3206785246863'), ('Cersei', '+14357535455'), ('Davos', '+244562726258'), ('Arya', '+4407485376242')])
+    dict_items([('Arya', '+4407485376242'), ('Brienne', '+3206785246863'), ('Cersei', '+14357535455'), ('Davos', '+244562726258')])
+
+> **Important**: dictionaries are *unordered*, which means that while it may
+> seem reasonable that you've defined `my_phone_book` above with the keys
+> ordered alphabetically, *that's not now how Python stores them*, so the
+> results above may differ in order from your output.  Typically if you need
+> your dictionary to be ordered, you'll use a list of lists, or an
+> `OrderedDict` (a topic for another day). 
 
 As you can see, `.keys()` and `.values()` do what you'd expect: they return the
 keys and values respectively.  You may have noticed however that rather than a
@@ -293,19 +300,19 @@ anything with them other than read them as a complete entity, you'll have to
 cast them as a list:
 
     >>> print(list(my_phone_book.values()))
-    ['+3206785246863', '+14357535455', '+244562726258', '+4407485376242']
+    ['+4407485376242', '+3206785246863', '+14357535455', '+244562726258']
 
-    >>> print(list(my_phone_book.values())[2])
+    >>> print(list(my_phone_book.values())[3])
     '+244562726258'
 
 The last one there, `.items()` is interesting.  It returns all of the data in
 your dictionary, but dumps it out as `dict_items` which is a sort of *tuple of
 tuples*.  This allows you to reference your dictionary with list syntax:
 
-    >>> print(tuple(my_phone_book.items())[0])
+    >>> print(tuple(my_phone_book.items())[1])
     ('Brienne', '+3206785246863')
 
-    >>> print(tuple(my_phone_book.items())[0][1])
+    >>> print(tuple(my_phone_book.items())[1][1])
     '+3206785246863'
 
 Truth be told though, you probably won't be accessing these values directly