[3.5] Fix small typos in introduction and datastructures of tutorial (GH-272) (GH-299)

(cherry picked from commit 5bd5b9d81322d2cb6edd5f3804a347f8b2e65a15)
(cherry picked from commit 8c5e190d360b9f1a08c9fff249ae80d9c18007d5)
(cherry picked from commit 53c1892dc3de1de612b1cf95dc7bf09f82c1babf)

2 files changed, 32 insertions, 29 deletions

diff --git a/Doc/tutorial/datastructures.rst b/Doc/tutorial/datastructures.rst
index b39bdf4..6140ece 100644
--- a/Doc/tutorial/datastructures.rst
+++ b/Doc/tutorial/datastructures.rst
@@ -22,11 +22,11 @@ objects:
    Add an item to the end of the list.  Equivalent to ``a[len(a):] = [x]``.
 
 
-.. method:: list.extend(L)
+.. method:: list.extend(iterable)
    :noindex:
 
-   Extend the list by appending all the items in the given list.  Equivalent to
-   ``a[len(a):] = L``.
+   Extend the list by appending all the items from the iterable.  Equivalent to
+   ``a[len(a):] = iterable``.
 
 
 .. method:: list.insert(i, x)
@@ -60,11 +60,16 @@ objects:
    Remove all items from the list.  Equivalent to ``del a[:]``.
 
 
-.. method:: list.index(x)
+.. method:: list.index(x[, start[, end]])
    :noindex:
 
-   Return the index in the list of the first item whose value is *x*. It is an
-   error if there is no such item.
+   Return zero-based index in the list of the first item whose value is *x*.
+   Raises a :exc:`ValueError` if there is no such item.
+
+   The optional arguments *start* and *end* are interpreted as in the slice
+   notation and are used to limit the search to a particular subsequence of
+   the list.  The returned index is computed relative to the beginning of the full
+   sequence rather than the *start* argument.
 
 
 .. method:: list.count(x)
@@ -94,28 +99,26 @@ objects:
 
 An example that uses most of the list methods::
 
-   >>> a = [66.25, 333, 333, 1, 1234.5]
-   >>> print(a.count(333), a.count(66.25), a.count('x'))
-   2 1 0
-   >>> a.insert(2, -1)
-   >>> a.append(333)
-   >>> a
-   [66.25, 333, -1, 333, 1, 1234.5, 333]
-   >>> a.index(333)
-   1
-   >>> a.remove(333)
-   >>> a
-   [66.25, -1, 333, 1, 1234.5, 333]
-   >>> a.reverse()
-   >>> a
-   [333, 1234.5, 1, 333, -1, 66.25]
-   >>> a.sort()
-   >>> a
-   [-1, 1, 66.25, 333, 333, 1234.5]
-   >>> a.pop()
-   1234.5
-   >>> a
-   [-1, 1, 66.25, 333, 333]
+    >>> fruits = ['orange', 'apple', 'pear', 'banana', 'kiwi', 'apple', 'banana']
+    >>> fruits.count('apple')
+    2
+    >>> fruits.count('tangerine')
+    0
+    >>> fruits.index('banana')
+    3
+    >>> fruits.index('banana', 4)  # Find next banana starting a position 4
+    6
+    >>> fruits.reverse()
+    >>> fruits
+    ['banana', 'apple', 'kiwi', 'banana', 'pear', 'apple', 'orange']
+    >>> fruits.append('grape')
+    >>> fruits
+    ['banana', 'apple', 'kiwi', 'banana', 'pear', 'apple', 'orange', 'grape']
+    >>> fruits.sort()
+    >>> fruits
+    ['apple', 'apple', 'banana', 'banana', 'grape', 'kiwi', 'orange', 'pear']
+    >>> fruits.pop()
+    'pear'
 
 You might have noticed that methods like ``insert``, ``remove`` or ``sort`` that
 only modify the list have no return value printed -- they return the default
diff --git a/Doc/tutorial/introduction.rst b/Doc/tutorial/introduction.rst
index 2140329..af277ce 100644
--- a/Doc/tutorial/introduction.rst
+++ b/Doc/tutorial/introduction.rst
@@ -356,7 +356,7 @@ The built-in function :func:`len` returns the length of a string::
       Information about string formatting with :meth:`str.format`.
 
    :ref:`old-string-formatting`
-      The old formatting operations invoked when strings and Unicode strings are
+      The old formatting operations invoked when strings are
       the left operand of the ``%`` operator are described in more detail here.