'''

Secret Message: AP-CSP Python Take Home Test

--------

Name: Period:

Create a class called Secret_Message. This class has one

class variable named key_list, and two instance variables;

an integer named stepper and a dictionary name key. It also

has two instance methods named encrypt and decrypt.

Encrypt accepts a string message argument and

returns an encrypted string. Decrypt takes an encrypted

string argument and returns the decrypted message string

value.

Before creating any instance objects from the

class, the class variable must be set equal to a randomized

list of integers between 1 and 225. When an object of

Secret_Message is instantiated, it is passed a stepper

integer of either 2, 3, or 4. This value will then be used

to create a key from the key_list by selecting 52 key values

from every 2nd, 3rd, or 4th value from the key_list. Each

value is paired in a key dictionary with the letters of the

alphabet*.

When a text string is passed to the encryt message, each

letter is encrypted as an integer by looking up its integer

equivalent in the key dictionary, saving it to a temporary

list, and then returning the completed list cast to string.

When the same string returned from the encrypt method is

passed to the decryt method, the original string should be

returned.

Be sure and test your class by creating an instance and

encrypting and decrypting a message in the interactive

window with logging turned on. The original code and the

log file must both be submitted. Code will be graded on

completion (80%), structure (10%), and use of comments (10%)

* Hint: The dictionary will require two inner/outer loop

constructs where the outer loops steps through the

values in the key_list and the inner loops pair them

with each letter of the alphabet and adds the pairs

to the dictionary.

The key should end up looking something like:

key = {'a':155, 'b':26, ... 'A':92, 'B': 54, ...}

To generate the letters of the alphabet, use:

for lowercase in range(ord('a'),ord('z')+1):

lower = chr(lowercase)

or

for uppercase in range(ord('A'),ord('Z')+1):

upper = chr(uppercase)

'''