Added a few cross-references and a few more links.

Added a note that __import__ is "advanced" since that's the first
function that appears and looks scary for newcomers.
Added an example for enumerate since I don't think it is
immediately obvious how it works.

Doc-26/library/functions.rst

@@ -16,7 +16,12 @@ available.  They are listed here in alphabetical order.
       module: rexec
       module: imp
 
-   This function is invoked by the :keyword:`import` statement.  It mainly exists
+   .. note::
+
+    This is an advanced function that is not needed in everyday Python
+    programming.
+
+   The function is invoked by the :keyword:`import` statement.  It mainly exists
    so that you can replace it with another function that has a compatible
    interface, in order to change the semantics of the :keyword:`import` statement.
    For examples of why and how you would do this, see the standard library modules
@@ -126,7 +131,8 @@ available.  They are listed here in alphabetical order.
 
 .. function:: callable(object)
 
-   Return true if the *object* argument appears callable, false if not.  If this
+   Return :const:`True` if the *object* argument appears callable,
+   :const:`False` if not.  If this
    returns true, it is still possible that a call fails, but if it is false,
    calling *object* will never succeed.  Note that classes are callable (calling a
    class returns a new instance); class instances are callable if they have a
@@ -138,7 +144,8 @@ available.  They are listed here in alphabetical order.
    Return a string of one character whose ASCII code is the integer *i*.  For
    example, ``chr(97)`` returns the string ``'a'``. This is the inverse of
    :func:`ord`.  The argument must be in the range [0..255], inclusive;
-   :exc:`ValueError` will be raised if *i* is outside that range.
+   :exc:`ValueError` will be raised if *i* is outside that range. See
+   also :func:`unichr`.
 
 
 .. function:: classmethod(function)
@@ -346,7 +353,14 @@ available.  They are listed here in alphabetical order.
    returned by :func:`enumerate` returns a tuple containing a count (from zero) and
    the corresponding value obtained from iterating over *iterable*.
    :func:`enumerate` is useful for obtaining an indexed series: ``(0, seq[0])``,
-   ``(1, seq[1])``, ``(2, seq[2])``, ....
+   ``(1, seq[1])``, ``(2, seq[2])``, .... For example::
+
+    >>> for i, season in enumerate(['Spring', 'Summer', 'Fall', 'Winter')]:
+    >>>	    print i, season
+    0 Spring
+    1 Summer
+    2 Fall
+    3 Winter
 
    .. versionadded:: 2.3
 
@@ -1086,6 +1100,14 @@ available.  They are listed here in alphabetical order.
    acceptable to :func:`eval`; its goal is to return a printable string.  If no
    argument is given, returns the empty string, ``''``.
 
+   For more information on strings see :ref:`typesseq` which describes
+   sequence functionality (strings are sequences), and also the
+   string-specific methods described in the :ref:`string-methods`
+   section. To output formatted strings use template strings or the
+   ``%`` operator described in the :ref:`typesseq-strings` section. In
+   addition see the :ref:`stringservices` section. See also
+   :func:`unicode`.
+
 
 .. function:: sum(iterable[, start])
 
@@ -1166,7 +1188,8 @@ available.  They are listed here in alphabetical order.
    *i*.  For example, ``unichr(97)`` returns the string ``u'a'``.  This is the
    inverse of :func:`ord` for Unicode strings.  The valid range for the argument
    depends how Python was configured -- it may be either UCS2 [0..0xFFFF] or UCS4
-   [0..0x10FFFF]. :exc:`ValueError` is raised otherwise.
+   [0..0x10FFFF]. :exc:`ValueError` is raised otherwise. For ASCII and 8-bit
+   strings see :func:`chr`.
 
    .. versionadded:: 2.0
 
@@ -1196,6 +1219,14 @@ available.  They are listed here in alphabetical order.
    string version or representation is requested and then converted to a Unicode
    string using the codec for the default encoding in ``'strict'`` mode.
 
+   For more information on Unicode strings see :ref:`typesseq` which describes
+   sequence functionality (Unicode strings are sequences), and also the
+   string-specific methods described in the :ref:`string-methods`
+   section. To output formatted strings use template strings or the
+   ``%`` operator described in the :ref:`typesseq-strings` section. In
+   addition see the :ref:`stringservices` section. See also
+   :func:`str`.
+
    .. versionadded:: 2.0
 
    .. versionchanged:: 2.2