codePost snippet to automatically compute a grade based on extracting data from one of the files of the submissions (such as an auto-grader output), finalize all submissions of an assignment, and automatically add a comment that sets the grade of the submission

codePost-compute-grade-from-file-contents.py

import re
import codepost

# ================================================================
# VARIABLE PARAMETERS
# get the API key here: https://codepost.io/settings
API_KEY = "... see above where to get this ..."
COURSE_NAME = "COS126"
COURSE_TERM = "S2023"
ASSIGNMENT = "Atomic"
AUTOGRADER_OUTPUT_FILE = "TESTS.txt"
DEFAULT_GRADER = "lumbroso@princeton.edu"
# + edit the patterns in the parse_test_results function below to
#   match the output of your autograder
# ================================================================

# authenticate
codepost.configure_api_key(API_KEY)

# retrieve the course, and then the assignment
# (will crash if the user of the API key doesn't have access to the course)
course = codepost.course.list_available(name=COURSE_NAME, period=COURSE_TERM)[0]
assignment = course.assignments.by_name(name=ASSIGNMENT)

# function that parses the autograder output of submissions to extract results

def parse_test_results(submission, tests_file_name=AUTOGRADER_OUTPUT_FILE):
    # Each submission contains a TESTS.txt file that at some point
    # contains the text:
    # ================================
    # Correctness:  42/42 tests passed
    # Memory:  10/10 tests passed
    # Timing:  19/19 tests passed
    # ================================
    
    match = re.search(
        "Correctness:.*(\nMemory:.*)+(\nTiming:.*)+\n",
        submission.files.by_name(tests_file_name).code,
        re.MULTILINE
    )
    if match is None:
        return
    
    lines = match.group(0).splitlines()
    
    def parse_test_result(line):
        # Assumes the line is of the form: ".....  N/M ........."
        # and extracts (N, M) as a tuple of integers
        match = re.search("(?P<passed>\d+)/(?P<total>\d+)", line)
        if match is None:
            return
        return (int(match.group("passed")), int(match.group("total")))
    
    results = list(map(parse_test_result, lines))
    
    return results


# main loop
for submission in assignment.list_submissions():
    
    # claim submission (must assign a grader, here I assign myself)
    submission.grader = DEFAULT_GRADER
    
    # save changes (necessary to be able to assign comments)
    submission.save()

    # then select a file on which to add a comment
    test_file = submission.files.by_name(name=AUTOGRADER_OUTPUT_FILE)
    
    # remove all previous comments
    # (to avoid duplicates, if we rerun this process several times)
    for comment in test_file.comments:
        comment.delete()
    
    # compute the grade
    
    test_results = parse_test_results(submission)
    tests_passed = sum(map(lambda x: x[0], test_results))
    tests_total = sum(map(lambda x: x[1], test_results))
    grade = (
        round(float(tests_passed)/float(tests_total)*100.0, 2)
        if float(tests_total) > 0 else 0
    )
    
    # describe and create the comment
    
    comment = {
        'file': test_file.id,
        'text': (
            "Your final grade is: {} / 100.0\n\n" +
            "Please look at {} for a detailed computation.\n\n" +
            "This is computed directly from the number of " +
            "auto-grader tests passed."
        ).format(grade, AUTOGRADER_OUTPUT_FILE),
        'pointDelta': -grade,
        'rubricComment': None,
        'startChar': 0,
        'endChar': 1,    
        'startLine': 1,
        'endLine': 1,    
    }

    codepost.comment.create(**comment)
    
    # finalize the submission
    # (so it is visible to students, once the assignment is "published")
    submission.isFinalized = True
    submission.save()