Project 8: Scripts!

Reading! !
Lecture notes for May 30 to June 4 (available on the class web sites).!
Warning!
This week’s projects uses Python library functions that interact with your operating
system, including functions that delete files. We strongly recommend following the
incremental development style for these projects. While you are debugging your
program, have it print a message like “deleting file X” instead of calling the function
that deletes the file. When you are sure the program is doing the right thing add the
statement that calls the function that deletes the file.!
Test Data!
The projects require you to write a set of “scripts” that work with files and directories.
To test the scripts, download a file named FederalistPapers.tgz. When you
unpack the file you will have new folder named FederalistPapers. !
This folder has a set of files created by LaTeX, a document formatting system widely
used in math and science. Files with names that end with .tex are the document
files; these are plain text files containing markup commands that tell LaTeX how to
format the document. When LaTeX runs it generates lots of temporary files with
names that end .aux, .log, etc.!
A Note for Windows Users!
If you use Microsoft Windows you will need to download and install a package named
Cygwin. This package includes wc, grep, and several other useful Unix utilities.!
Programming Projects!
1. Write a program named cleanup.py that deletes all the temporary files from a
LaTeX project. The command line argument should be the name of the top level
directory containing the main .tex file. The program should delete all the
temporary files in that directory and in any subdirectories.!
When your program runs it should print the names of the files it is deleting. This
is what you should see when you run the program with the FederalistPapers
directory:!
% python3 cleanup.py FederalistPapers
FederalistPapers/TheFederalistPapers.aux
FederalistPapers/TheFederalistPapers.log
FederalistPapers/TheFederalistPapers.pdf
FederalistPapers/TheFederalistPapers.toc
FederalistPapers/Legalese/license.aux
CIS 211!
Spring 2014FederalistPapers/Number1/federalist1.aux
FederalistPapers/Number2/federalist2.aux
FederalistPapers/Number3/federalist3.aux
For this project a temporary file is any file that has a name that ends with one of
these extensions:!
.aux .idx .ilg .ind .log .pdf .toc
2. Write a program named backup.py that copies the files from a LaTeX project to a
backup directory. Name your backup directory versions. The first time the
program runs it should create the versions folder and then copy the project to a
folder named 1 inside versions. If the program is run again it should create
another new folder inside versions. The second backup will be saved in
versions/2, the third in versions/3, and so on.!
3. Write a program named pstats.py that will compute some basic statistics about
a LaTeX project. The output will use the same format as the Unix utility named
wc (word count). This is what you should see when you run your program with
the FederalistPapers directory:!
% python3 pstats.py FederalistPapers
4 8 915 7546 FederalistPapers
This output says the FederalistPapers project has 4 chapters and 8 sections,
and that there are a total of 915 lines and 7546 words in all the .tex files.!
To count the number of chapters your program should run the Unix utility named
grep with this command (where file.tex is the name of one of the LaTeX
source files):!
% grep '\\chapter' file.tex
To count sections use the same command, but with section instead of chapter.
To count the number of lines and words in a file your program should run the wc
command and capture the results.!
Hint: use Python’s “raw string” format when you create a string containing a Unix
command. For example, this is the best way to make the command that
searches for lines containing the LaTeX \chapter command:!
cmnd = r"grep '\\chapter' {}".format(filename)
See the lecture notes for more information about raw strings and why they’re
useful.!Extra Credit Ideas!
• Have your backup.py script ignore temporary files (files with names
ending .aux, .idx, etc).!
• Instead of deleting files copy them to a trash folder. Either create a trash folder in
the project directory or figure out how to copy to your computer’s trash folder.!
• Write a script that recovers deleted files by removing them from the trash and
restoring them to the project directory.!