When organizing submissions for grading, Otter supports two major categories of exports:

  • 3rd party collection exports, or
  • instructor-made metadata files

These two categories are broken down and described below.

3rd Party Exports

If you are using a grading service like Gradescope or an LMS like Canvas to collect submissions, Otter can interpret the export format of these 3rd party services in place of a metadata file. To use a service like Gradescope or Canvas, download the submissions for an assignment, unzip the provided file, and then proceed as described in the command line usage using the metadata flag corresponding to your chosen service.

For example, if I had a Canvas export, I would unzip it, cd into the unzipped directory, copy my tests to ./tests, and run

otter -c

to grade the submissions (assuming no extra requirements, no PDF generation, and no support files required).

Metadata Files

If you are not using a service like Gradescope or Canvas to collect submissions, instructors can also create a simple JSON- or YAML-formatted metadata file for their students’ submissions and provide this to Otter.

The strucure of the metadata is quite simple: it is a list of 2-item dictionaries, where each dictionary has a student identifier stored as the identifier key and the filename of the student’s submission as filename. An example of each is provided below.

YAML format:

- identifier: 0
  filename: test-nb-0.ipynb
- identifier: 1
  filename: test-nb-1.ipynb
- identifier: 2
  filename: test-nb-2.ipynb
- identifier: 3
  filename: test-nb-3.ipynb
- identifier: 4
  filename: test-nb-4.ipynb

JSON format:

    "identifier": 0,
    "filename": "test-nb-0.ipynb"
    "identifier": 1,
    "filename": "test-nb-1.ipynb"
    "identifier": 2,
    "filename": "test-nb-2.ipynb"
    "identifier": 3,
    "filename": "test-nb-3.ipynb"
    "identifier": 4,
    "filename": "test-nb-4.ipynb"

A JSON- or YAML-formatted metadata file is specified to Otter using the -j or -y flag, respectively. Each flag requires a single argument that corresponds to the path to the metadata file. See the “Basic Usage” section of the CLI documentation for more information.