Week 2: Functions and expressions

Note: before you try an exercise in the interpreter, solve/explain it using paper and pen.
  1. Consider the following functions: 
    	def double(n):
	    return n*2

	def double_p(n):
	    print n*2
   
        >>> double(5)
        10
        >>> double_p(5)
        10
    Explain the difference between the two and why one of them is to be preferred over the other.
  2. Do the exercises in Chapter 2.
  3. Do the exercises in Chapter 3.