# This code illustrates how scope functions.

x = 0 # x is a global variable 
def main():
     #  NOT the same x, y, z as in the average function
     a = 1.3  # local variable to main()   
     b = 2.5  # local variable to main()
     c = 6.8 # local variable to main()

     # arguments in a function call do NOT have to have the same
     #  names as formal function parameters

     x = average(a, b, c)	# local x (to main()) being used here
     print "average =",  x

     if x > 10:		
         var1 = 20  # this variable only exists in 
                    # the body of the if statement!				
                    # end of var1's scope

     print var1	  # would be illegal! - need to either remove or change 


def average(x, y, z):
  # the variables x, y, and z are LOCAL variables to this function
  #  NOT the same as the global x.
  # If we changed the argument x to say k then the global x value will be used.
  total = x + y + z		# total is another variable, local x being used here
  return (total / 3.0)

main()