Working example of nbgrader from the command line using R and testthat:

Dependencies:

(click on links for download and installation instructions)

• Python & Jupyter
• nbgrader
• R
• IR kernel
• testthat

The Demo:

1. Clone/download this repository and navigate into its root directory in the terminal. Note - I used nbgrader quickstart course_id to generate course template and nbgrader config file.

2. Added this to nbgrader_config.py to specify the “exchange” directory to be /tmp/exchange and to enable R to be used with nbgrader:

c.Exchange.root = "/tmp/exchange"

## The delimiter marking the beginning of a solution
c.ClearSolutions.begin_solution_delimeter = 'BEGIN SOLUTION'

## The code snippet that will replace code solutions
c.ClearSolutions.code_stub = {
    "r": "# your code here\nfail() # No Answer - remove if you provide an answer",
    "python": "# your code here\nraise NotImplementedError",
    "javascript": "// your code here\nthrow new Error();"
}

## The delimiter marking the end of a solution
c.ClearSolutions.end_solution_delimeter = 'END SOLUTION'

note - thanks to https://github.com/sagemathinc/cocalc/wiki/nbgrader for suggestions on how to modify the config file to work with R!

3. "refresh" the “exchange” directory:

# remove existing directory, so we can start fresh for demo purposes
rm -rf /tmp/exchange

# create the exchange directory, with write permissions for everyone
mkdir /tmp/exchange
chmod ugo+rw /tmp/exchange

4. Create the assignment with solutions and tests in a Jupyter notebook. It is important to ensure you have the assignment toolbar and choose the correct cell types from the drop-down menu. You can access this via View > Cell Toolbar > Create Assignment. Then assign points for the question in the autograder test cells.

5. Create the student version of the assignments:

nbgrader assign ps1

note - in this example it is assumed we would use some mechanism (not nbgrader) to then distribute copies of this assignment and then collect them into the submitted directory after the students worked on them. Here for this demo, I manually create the submitted directory and the student directories inside this (which correspond to the students in the config file):

mkdir submitted
mkdir submitted/hacker
cp -r release/ps1 submitted/hacker/ps1
mkdir submitted/bitdiddle
cp -r release/ps1 submitted/bitdiddle/ps1

I then manually edited the submitted notebooks with sample work a student might hand in.

6. Run the autograder:

nbgrader autograde ps1

7. Export the database to a csv:

nbgrader export