revising released notebooks which are downloaded by students

nbgrader_revision.py

import nbformat
import os

release_dir = "/home/randy3k/nbgrader/sts437/release"
assignment = "sts437-hw1"
assignment_dir = os.path.join(release_dir, assignment)
problems = [f for f in os.listdir(assignment_dir) if os.path.splitext(f)[1] == ".ipynb"]
users = [d for d in os.listdir("/home") if os.path.isdir("/home/{}".format(d))]


def solution_cells(nb):
    ret = {}
    for cell in nb.cells:
        if "nbgrader" in cell.metadata:
            if cell.metadata.nbgrader.solution:
                grade_id = cell.metadata.nbgrader.grade_id
                ret.update({grade_id: cell.source})
    return ret

for u in users:
    for p in problems:
        try:
            target = "/home/{}/{}/{}".format(u, assignment, p)
            nb_user = nbformat.read(target, 4)
            
            source = os.path.join(release_dir, "{}/{}".format(assignment, p))
            nb_skeleton = nbformat.read(source, 4)

            solutions = solution_cells(nb_user)
            for cell in nb_skeleton.cells:
                if "nbgrader" in cell.metadata:
                    if cell.metadata.nbgrader.solution:
                        grade_id = cell.metadata.nbgrader.grade_id
                        if grade_id in solutions:
                            cell.source = solutions[grade_id]
                
            nbformat.write(nb_skeleton, target, 4)
            print(target)
        except Exception as e:
            print(e)