Added demo example to SVN

doc/examples/example-demo.py

@@ -0,0 +1,40 b''
+"""A simple interactive demo to illustrate the use of IPython's Demo class.
+
+Any python script can be run as a demo, but that does little more than showing
+it on-screen, syntax-highlighted in one shot.  If you add a little simple
+markup, you can stop at specified intervals and return to the ipython prompt,
+resuming execution later.
+"""
+
+print 'Hello, welcome to an interactive IPython demo.'
+print 'Executing this block should require confirmation before proceeding,'
+print 'unless auto_all has been set to true in the demo object'
+
+# The mark below defines a block boundary, which is a point where IPython will
+# stop execution and return to the interactive prompt.
+# Note that in actual interactive execution, 
+# <demo> --- stop ---
+
+x = 1
+y = 2
+
+# <demo> --- stop ---
+
+# the mark below makes this block as silent
+# <demo> silent
+
+print 'This is a silent block, which gets executed but not printed.'
+
+# <demo> --- stop ---
+# <demo> auto
+print 'This is an automatic block.'
+print 'It is executed without asking for confirmation, but printed.'
+z = x+y
+
+print 'z=',x
+
+# <demo> --- stop ---
+# This is just another normal block.
+print 'z is now:', z
+
+print 'bye!'