Question 1 Exercise 72 from Think Python 2nd Edition by Alle
     Question 1 (Exercise 7.2 from Think Python 2nd Edition by Allen Downey) Built-in function eval takes a string and evaluates it using the Python interpreter. For example: >>eval(\'1 + 2* 3\') >>>import math eval\'math.sqrt(5)\") 2.23606797749979 eval\'type (math.pi)\")  Write a fucntion called eval_loop that iteractively prompts the user, takes the resulting input and evaluates it using eval , and prints the result. It should continue until the user enters \'done\', and then returns the value of the last expression it evaluated.  
  
  Solution
# The built-in function eval takes a string and evaluates it using the Python interpreter.
 def eval_loop():
 while True:
 n = raw_input(\'Input?\ :: \')
 if n == \'done\':
 break
 else:
 result = eval(n)
 print result
 print result
eval_loop()

