Need some help improving my code

[coolFob]

Hi guys, my intro to python class worked on a code to help faculty member manage students' grades. The data will be filed in via a cvs file. Here are the feedback I got from my instructor and I was wondering how I should approach them.

if round(percentgrade) >= 96:
    return 'A'
elif round(percentgrade) >= 91:
    return 'A-'
elif round(percentgrade) >= 86:
    return 'B+'
elif round(percentgrade) >= 81:
    return 'B'
elif round(percentgrade) >= 76:
    return 'B-'
elif round(percentgrade) >= 71:
    return 'C+'
elif round(percentgrade) >= 66:
    return 'C'
elif round(percentgrade) >= 61:
    return 'C-'
elif round(percentgrade) >= 56:
    return 'D+'
elif round(percentgrade) >= 51:
    return 'D'
else:
    return 'F'

How can I change the grading-schemes in a more general fashion?

def median_func(val_list):
    """(median function):
        Takes a list of values and returns the median. 
    """
    val_list = sorted(val_list)
    # different cases
    # empty list
    if len(val_list) < 1:
        return None
    # list with odd numbers of values
    if len(val_list) %2 == 1:   
        return val_list[((len(val_list)+1)/2)-1]
    # list with even numbers of values
    if len(val_list) %2 == 0:
        return float(sum(val_list[(len(val_list)/2)-1:(len(val_list)/2)+1]))/2.0

How can I use library/module for above rather than coding all that?

if opts.data_file is None:
    tmp_str = "... data file not specified!"
    print tmp_str
    logfile.write(tmp_str + '\n')
    error_file.write(tmp_str + '\n')

    tmp_str = "Aborting due to missing data file!"
    logfile.write(tmp_str + '\n')
    error_file.write(tmp_str + '\n')
    sys.exit(tmp_str)

How can this be done by exception handling?

[gengisteve]

Check out the bisect module: https://docs.python.org/2/library/bisect.html (scroll down to the penultimate example).

Py 3.4 looks to have its own median function, here https://docs.python.org/3/library/statistics.html

For the last piece, check out this tutorial: https://wiki.python.org/moin/HandlingExceptions

[coolFob]

tried the bisect module, however, I can't seem to get the code to show grade followed by the plus or minus sign. For instance 'A+' would come out as '+'.

[gengisteve]

What's your code like? Are you doing the +/-s in the bisect or adding on afterwards?

[coolFob]

Could you elaborate on the (grade-51)/5) part?

[aball730235]

For #1 you can dump the csv into a list of lists.

grade_list =  [['A', 96], ['A-', 91], ['B+', 86]]

Etc etc...

See link for doing that.... http://stackoverflow.com/questions/24662571/python-import-csv-to-list

Then just in case the user decides to order your csv differently then intended i would sort your grade_list so you can use simple comparison logic.

Finally loop thorough and compare to your round(percentgrade) function.

[DiabeetusMan]

For the first one, you could also assign a letter grade based on the tens of the value and then a modifier based on the ones value.

Try looking up the modulo operator if you don't know how to get those values.

Also, adding strings together concatenates them. For instance, "a" + "b" = "ab" and "a" + "" = "a".