EECS 12 Summer 2006 Homework 5

General Instructions

Please place your programs in seperate files named as described in the problem. Improperly named programs will not count. Turn in your files by placing them in the dropbox. Please be mindful of the late policy.

Grading

Correct	80%
Commented	10%
Attempted	10%

Problems

Problem 0: 50 points

Create a program that turns nested lists into tree objects and vice-versa.

• Create a class called TreeNode
• Create a function makeTree(nestedList) that takes lists of the form [value, childList] and recursively creates a tree out of TreeNodes which it then returns.
• Create a function printTree(root, level) which prints out a tree recursively, with level number of * before each entry.
• Create a recursive function dumpToList(root) that takes a tree object and returns it converted into a list.

Hint: You can multiply a string by an integer to get multiple copies of a string. '*'*5 is the same as '*****'

You should be able to create a list in the specified format, convert it into a tree, convert that tree into a list, and then convert the list into a tree again. When printed, the trees should look the same.

Include the following test code in your file:

root = MakeTree([1,[[2,[[3,[]],[4,[]]]],[5,[[6,[]],[7,[]]]]]])
asList = DumpToList(root)
PrintTree(root,0)
PrintTree(MakeTree(asList),0)

It should print out the following:

 1
* 2
** 3
** 4
* 5
** 6
** 7
 1
* 2
** 3
** 4
* 5
** 6
** 7

Problem 1: 50 points

Modify your program from 4.1:

• Call the new one analyzeSafe.py
• Catch TypeError for when the user gives the wrong number of arguments.
• Catch ValueError for when the user gives something that is not a number when it should be (i.e., something like 'cow' instead of 5)
• Allow the user to save and load data from the disk using the new commands savedisk and loaddisk. Each one should expect the user to give the name of the file. loaddisk should have its own try...except to catch IOError if the file does not exist.

? range 1-
Bad value
? range 10 11
Wrong number of arguments
? range 10
Result: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
? savedisk ten
Result: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
? quit
Goodbye!
######### NEW RUN OF PROGRAM ########
? loaddisk cow
No such file: cow
Result: []
? loaddisk ten
Result: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]