=== Python Lab III

==== Objective

  1. Learn about modules, imports, listing module contents, standard
     modules.

  2. Learn to build simple Python apps.

==== Required Reading

  * Section 'Modules' of the http://docs.python.org/tutorial/[Python
    Tutorial].

==== Modules

  1. Write a module with the following contents, and name it `fibo.py`.
+
------
# Fibonacci numbers module

def fib(n):    # write Fibonacci series up to n
    a, b = 0, 1
    while b < n:
        print b,
        a, b = b, a+b

def fib2(n): # return Fibonacci series up to n
    result = []
    a, b = 0, 1
    while b < n:
        result.append(b)
        a, b = b, a+b
    return result
------
+
  2. Import the module.
  3. Access the function `fib` defined within the module.
  4. Access and print the module's name.
  5. Assign a local name for the function `fibo.fib`, and invoke the
     function using local name.
  6. Import the function `fibo.fib` directly into the local name
     `fib`.

------
>>> import fibo

>>> fibo.fib(1000)
1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987

>>> print fibo.__name__
fibo

>>> myfib = fibo.fib
>>> myfib(500)
1 1 2 3 5 8 13 21 34 55 89 144 233 377

>>> from fibo import fib
>>> fib(500)
1 1 2 3 5 8 13 21 34 55 89 144 233 377
>>>
------

==== Builtins and Standard Modules

Perform the following operations at the Python interpreter prompt.

  1. Import the `random` module.
  2. List the contents of the `random` module.
  3. Print the help information for `random.randint`.
  4. Invoke the `random.randint` function.
  5. List the builtin functions.
  6. Create a variable and a function and list the contents of the
     local name space.

------
>>> import random

>>> dir(random)
[...'randint', 'random', 'randrange'...]

>>> help(random.randint)
Help on method randint in module random:
<BLANKLINE>
randint(self, a, b) method of random.Random instance
    Return random integer in range [a, b], including both end points.
<BLANKLINE>

>>> random.randint(1, 99)
57

>>> dir(__builtins__)
['ArithmeticError'...'zip']

>>> def testfunc():
... 	pass
... 
>>> testvar = 10
>>> dir()
['__builtins__'...'testfunc', 'testvar']
>>>
------

==== Arithmetic Quiz

In the Arithmetic Quiz program, the computer prints an arithmetic
expression using the two 2 digit numbers (selected in random) and the
operator + or - (selected in random). The user has to find out the
value of the expression. Based on the user's input the computer
updates the user's score. After 20 repetitions the computer prints the
user's score. A sample run is shown below.

-----
10 + 15 ? 25
Correct!
21 + 33 ? 55
Wrong!
31 - 10 ? 21
Correct!
...
...
Your score is 18/20.
-----

Write a Python script that implements the Arithmetic Quiz.