Source code for area_volume

"""
Prints the area and volume of a cylinder. This module is used to illustrate 
the use of functions and how some functions return values and how others 
return nothing. 

Note that function ``area_and_volume`` does not return a value. As such
it returns the special value ``None``.

Example use of these functions::

   >>> print area_circle(5)
   >>> vc = volume_cylinder(5,10)
   >>> print "Volume of cylinder is", vc
   >>> area_and_volume(5,10)

"""

[docs]def area_circle(radius): """ Returns the area of a circle given the radius. """ pi = 3.14159 return pi * radius ** 2
[docs]def volume_cylinder(radius,height): """ Returns the volume of a cylinder given radius and height. """ pi = 3.14159 area = area_circle(radius) return area * height
[docs]def area_cylinder(radius,height): """ Returns the surface area of a cylinder given radius and height. """ pi = 3.14159 circle_area = area_circle(radius) height_area = 2 * radius * pi * height return 2*circle_area + height_area
[docs]def area_and_volume(radius, height): """ Prints the area and volume of a cylinder given radius and height. The function returns nothing, i.e. None. """ print "For a cylinder with radius", radius, "and height", height print "The surface area is ", area_cylinder(radius,height) print "The volume is ", volume_cylinder(radius, height)