Description
The Benghazi Congressional Hearing is currently in the news. One complaint is that the hearings are
expensive. How can we use data and Python to investigate that complaint? The costs of some
previous congressional hearings are in a file named hearings.txt. However, the dollar amounts in
that file need to be adjusted to account for inflation. To help with those adjustments, the inflation
figures for the past 100 years are in a file named inflation.txt.
In this assignment, you will develop a program to calculate and display the inflation-adjusted cost of
the congressional hearings.
Assignment Specifications
1. You will develop the Python program described below, paying particular attention to the required
functions.
2. Your program may not use sets or dictionaries.
3. Your programs may use any built-in or standard library functions; it may not import any modules
which are not in the Anaconda distribution.
4. You are provided with two input files: inflation.txt and hearings.txt . Your program
must work with files with the same name that have a different number of lines and values, but that are
formatted the same. Note that you are not to prompt for these file names; your program will just use
those names.
5. One function reads a file, skips past a specified number of header lines, reads values in specified
columns, and returns a list of lists where each nested list corresponds to the values read from one line
of the file.
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inflation.txt
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get_cols_from_file( “inflation.txt”, [0,-1], 1 )
The general form of the function is:
get_cols_from_file( str, list, int ) -> list (of lists)
where
• the first parameter (of type str) is the file name to read from;
• the second parameter (of type list) is a list of integers defining the columns to be read;
• and the third parameter (of type int) is the number of header lines to ignore.
The function will return a list of lists, where the nested lists contain the data from the specified
columns, in the order specified by the second parameter.
For example, given the file inflation.txt whose first lines are as follows:
YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC AVE
1914 2.0 1.0 1.0 0.0 2.1 1.0 1.0 3.0 2.0 1.0 1.0 1.0 1.0
1915 1.0 1.0 0.0 2.0 2.0 2.0 1.0 -1.0 -1.0 1.0 1.0 2.0 1.0
1916 3.0 4.0 6.1 6.0 5.9 6.9 6.9 7.9 9.9 10.8 11.7 12.6 7.9
1917 12.5 15.4 14.3 18.9 19.6 20.4 18.5 19.3 19.8 19.5 17.4 18.1 17.4
The following function call
get_cols_from_file( “inflation.txt”, [0,-1], 1 )
will return the following list
[ [‘1914’, ‘1.0’], [‘1915’, ‘1.0’], [‘1916’, ‘7.9’], [‘1917’, ‘17.4’], … ]
Note that outside of the function you will want to change the values in the lists to ints., e.g.
[ [1914, 1.0], [1915, 1.0], [1916, 7.9], [1917, 17.4], … ]
6. One function must take a dollar amount, year, and list of inflation percents, and adjust the amount
for inflation from the specified year to the present (2015).
The general form of the function is:
adjust_for_inflation( float, int, list ) -> float
where
• the first parameter (a float) is the original dollar amount;
• the second parameter (an int) is the year corresponding to the dollar amount;
• and the third parameter (a list) is a list of lists of ints (as described above) of years and
inflation values for the last 100 years in the form [ [year, inflation], [year, inflation], …]
The function will apply inflation for each year up to and including 2014 (because we haven’t reached
the end of 2015 yet). Since the original dollar amount occurred some time in the middle of the initial
year we will not count inflation for the first year. For example, the call
adjust_for_inflation( 14.4, 2002, inflation_list )
will apply inflation for the years 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013,
and 2014. It will return the float 18.9 (representing 18.9 million dollars, the inflation-adjusted value of
14.4 million dollars in 2002).
7. One challenge for calculating the inflation-adjusted amount for a given amount and year is to find
the index in the inflation_list of the (nested) list containing the inflation information for that
year. You must create and use the following function
find_index( int, list ) -> int
where
• the first parameter (an int) is a year;
• the second parameter (a list) is the inflation list (a list of lists of integers);
• and the return value is the index, in the input list, of the nested list that indicates the inflation
value for that year.
For example,
find_index( 1917, inflation_list )
will return 3 which is the index of the inflation information for the year 1917 in the inflation list.
8. You will use the provided function draw_bar_graph( list, list ) to display the
inflation adjusted values as a bar graph where
• the first parameter is a list of strings
• the second parameter is a corresponding list of numbers
The function is provided in the file draw_bar_graph.py and is complete. Copy the function into
your source code. You will call it with the list of names of congressional hearings and the list of their
corresponding costs as arguments.
9. You will create a function to create a new file named hearings_adjusted.txt that has the
same format as, but need not be copied from, the hearings.txt file. They can simply be string
literals in your function. The function will have the form
write_file( list )
where the only parameter is a list of inflation-adjusted hearing data.
The function does not return anything.
10. Your program will
i. Display the inflation-adjusted values in a bar graph (using the provided plotting function).
ii. Create a file named hearings_adjusted.txt that is formatted like the
hearings.txt input file, but with the original values replaced with inflation-adjusted
values.
Assignment Notes
1. Items 1-8 of the Coding Standard will be enforced for this project.
2. Function draw_bar_graph in the file named draw_bar_graph.py is complete as-is. You
should copy the source code for that function into your file proj07.py file. Remember to include
the import pylab line.
3. So you can check your calculations the inflation-adjusted values rounded to one decimal place for
the values in the file hearings.txt are:
Benghazi 4.5
Watergate 9.6
Iran-Contra 8.1
Starr 57.5
9-11 18.9
4. Here is what the bar graph will look like for those values:
Suggested Procedure
• Solve the problem using pencil and paper first. You cannot write a program until you have
figured out how to solve the problem. This first step may be done collaboratively with another
student. However, once the discussion turns to Python specifics and the subsequent writing of
Python statements, you must work on your own.
• Use the handin system to turn in the first version of your solution.
• Cycle through the steps to incrementally develop your program:
o Edit your library program to add new capabilities.
o Run the program and fix any errors.
o Use the handin system to submit the current version of your solution.
• Use the handin system to submit the final version of your solution.
• You would be wise to back up your files on your H: drive, also.
• Be sure to log out when you leave the room, if you’re working in a public lab.
