SetShowAnswerIfGraded.py

# import XML libraries
import xml.etree.ElementTree as ET
import sys
import os
import argparse

instructions = """
To use:
python3 SetShowAnswer.py show_answer_value path/to/problem/folder

show_answer_value can be one of the usual edX set:
  Always
  Answered
  Attempted
  Closed
  Finished
  CorrectOrPastDue
  PastDue
  Never

It can also be delete or default, in which case all
show_answer values are removed and the course-wide
default takes over.

Options:
  -h  Print help message and exit.

Last update: March 15th 2018
"""

# Here are all the options for show_answer values:
allAnswerValues = [
    "always",
    "answered",
    "attempted",
    "closed",
    "finished",
    "correctorpastdue",
    "pastdue",
    "never",
]


parser = argparse.ArgumentParser(usage=instructions, add_help=False)
parser.add_argument("-h", "--help", action="store_true")
parser.add_argument("answerSetting", default="finished")
parser.add_argument("directory", default=".")

args = parser.parse_args()
if args.help:
    sys.exit(instructions)
answerSetting = args.answerSetting.lower()

if not os.path.exists(args.directory):
    sys.exit("Directory not found: " + args.directory)

numfiles = 0

# Walk through the problems folder
for dirpath, dirnames, filenames in os.walk(args.directory):
    for eachfile in filenames:

        # Get the XML for each file
        tree = ET.parse(os.path.join(dirpath, eachfile))
        root = tree.getroot()

        # If this isn't a problem file, skip it.
        if root.tag != "problem":
            continue

        # Only set showanswer if the problem is graded.
        try:
            maxScore = float(root.attrib["weight"])
        except KeyError:
            # If weight isn't defined, it's 1.
            maxScore = 1
        except ValueError:
            print("Something weird is stored in problem weight for " + eachfile)
            continue

        if maxScore > 0:

            # Set the showanswer value
            if answerSetting in allAnswerValues:
                root.set("showanswer", answerSetting)
            elif answerSetting == "default" or answerSetting == "delete":
                try:
                    del root.attrib["showanswer"]
                except:
                    pass
            else:
                sys.exit("Invalid showanswer setting.")

        else:
            # If it's ungraded, let the course default take over.
            try:
                del root.attrib["showanswer"]
            except:
                pass

        # Save the file
        tree.write(
            os.path.join(dirpath, eachfile), encoding="UTF-8", xml_declaration=False
        )
        numfiles += 1


if numfiles == 0:
    print("No files found - wrong or empty directory?")
else:
    print("Show Answer options set for " + str(numfiles) + " files.")