Computer Science II Lab exercise set 8

CSC 242: Introduction to Computer Science II
Lab exercise set 8

Logistics
These exercises should be completed during the lab in order to receive full credit for the lab, you
must attend the session, remain in the lab for at least 45 minutes, and submit a file that contains
solutions to all these exercises.
You are encouraged to work in groups on lab exercises. If you do work with someone, you must
include the name(s) of your collaborator(s) at the top of the file you submit. For more
information about collaboration policies in this class, see the Academic Integrity policy posted to
the D2L site.
If you complete the lab exercise early, please review Chapter 10 in the textbook and work on the
eighth assignment. You must remain in the lab for at least 45 minutes to earn full credit. You are
only allowed to work on assignments with at most two-other people, either directly or indirectly,
who must be formally identified as part of your assignment submission. Please see the
assignment description and the course Academic Integrity pledge for the full description of the
process you must follow when completing assignments. If you need additional help on the
assignment, please ask the teaching assistant.
Exercises
Please remember that you are not allowed to consult online resources when completing lab
exercises. If you have questions, please either ask the teaching assistant or contact me by email.
Begin the lab by downloading the template file (csc242lab8.py) from the D2L site. It contains
the headers for the functions you will write. Do not modify the function names or parameters in
the template file. The functions written for this assignment must be recursive and must not use
global variables. You are also not allowed to use loops. In some cases certain built-in
functions are restricted in your solutions so carefully read each question. Solutions that
don't follow these guidelines will not earn full credit, even if they produce the correct
results in all cases.
1. Write a recursive function extractStr() that takes an arbitrarily nested list as a
parameter and returns a string that consists of the concatenation of all strings
found in the list. Note that the list may contain any Python type, not just strings.
Recall that you can determine whether an item is a string by writing type(item)
== str and whether an item is a list by writing type(item) == list. The function
should not use any loops. The only list functions you are allowed to use are len(),
indexing (lst[i] for an integer i), or slicing (lst[i:j] for integers i and j). You should
use string concatenation in writing your solution. If the list does not contain any
strings or is empty the function should return the empty string. The following
shows several sample runs of the completed function:
1. Write a recursive function totalNumericValue () that takes an arbitrarily
nested list as a parameter and returns a number that consists of the total of all
the numbers in the nested list. Note that the list may contain any Python type,
not just strings. Recall that you can determine whether an item is a int by writing
type(item) == int and whether an item is a list by writing type(item) == list. The
function should not use any loops. The only list functions you are allowed to use
are len(), indexing (lst[i] for an integer i), or slicing (lst[i:j] for integers i and j). If
the list does not contain any numbers or is empty the function should 0. The
following shows several sample runs of the completed function:
Submitting the exercises
You must submit your solutions to the exercises using the lab 8 dropbox on the D2L site. Submit
only a single Python file (e.g. csc242lab8.py) with each of the completed functions and classes
for the lab exercises in it. Submissions after the deadline listed above will be automatically
rejected by the system. See the syllabus for the grading policy.
Grading
The lab session is worth 10 points. If you complete the lab exercises before the end of the lab
session, please work on the eighth assignment. Remember that the rules for collaboration on
assignments is different from labs. Please review the Academic Integrity pledge for more
information. If you have questions about the assignment, please ask the teaching for help.