🐍Python

CodeGrade launched AutoTest V2 in early 2023.

In this tutorial we will guide you through all the steps to create your very first Python assignment in CodeGrade. For this tutorial we will be considering the example below. The zip folder contains a completed solution and a template file. Please make sure to save this file somewhere accessible on your computer:

A quick note about this example In this assignment, students have been asked to create a Python program that prints the first 'n' numbers of the Fibonacci sequence, where 'n' is determined by user input.

Step 1: Create an assignment

First, we need an assignment to work with. Whether CodeGrade is integrated in your LMS or you are using CodeGrade Standalone, you can follow the steps in the guide below to get started:

pageCreate assignment

Step 2: Configure submission settings

After you have created an assignment, the first step of setting up an assignment is to make sure that students can submit their code in the correct way. Because this example is straightforward and only requires a single solution file, we will offer the students the option to code in the CodeGrade Editor alongside the default File Uploader option.

  1. Navigate to the Assignment management menu by using the ⚙️ icon at the right-hand side of the page header

  2. Find the Submission settings under the General tab

  3. Enable the File uploader and Editor submission methods by clicking the respective check boxes.

  4. Enabling the Editor will reveal the Template files option. Unzip the Fibonacci.zip folder and upload Fibonacci/template/fibonacci.py as the template.

  5. Finalize your settings by clicking the "Submit" button.

It is good practice to provide a template file when enabling the Editor so that your students don't have to create their own file. This also avoids the risk of students submitting a file with the wrong name.

For more information about submission methods, see submission settings.

Step 3: Create a rubric

While you can always grade assignments directly by manually setting the Final grade, It's only possible to award points for your automatic tests with Rubrics. Rubrics also allow you to standardize the grading scheme for graders and they allow you to clarify the grading requirements to your students.

CodeGrade offers two types of rubric category:

  • Discrete category - Specify points in discrete steps (eg. 0, 5 or 10 points)

  • Continuous category - Specify points as a continuous scale (eg. 0 - 10)

  1. Navigate to the Rubric tab in the Assignment management menu.

  2. Select Create new rubric.

  3. Create 3 new Continuous Categories. Set the parameters as follows:

Category nameDescriptionMin - Max points

IO tests

Check that your program produces the expected output given a specific input.

0 - 50

Code structure tests

Check that your program uses the required code structures.

0 - 25

Flake8 tests

Check that your program conforms to the PEP8 style guide.

0 - 25

Step 4: Create automatic tests

Automatic tests are really what gives your students the opportunity to learn in a unique way. The immediate feedback they get from the automatic tests allow them to learn through trial and error by applying the instant feedback and resubmitting their work.

For this tutorial we will be setting up three automatic tests: IO tests, Semgrep code structure tests, and Flake8 code quality tests.

Step 4.1: Setup

Before actually creating the tests, we need to make sure we have the correct version of Python installed.

  1. Navigate to the Setup tab under the AutoTest settings.

  2. Add an Install Python block to your configuration.

  3. Select Python version 3.11 to install.

Step 4.2: Input/Output tests

Input/Output tests (or "IO tests" for short) are a great way of checking a program's functionality by providing various input cases that should result in a different outputs. You can create IO test cases in AutoTest v2 using the IO Test wrapper block and its corresponding Full match, Substring match, and Regex match blocks. For more information about these blocks, see Create an IO Test.

  1. Navigate to the Tests tab of the AutoTest settings.

  2. Add a Connect rubric block to your AutoTest configuration. Select the "IO tests" rubric category from the drop-down menu.

  3. Add an IO test block to your AutoTest configuration and nest it inside the Connect Rubric block.

  4. In the editor provided use the command python fibonacci.py to run the program.

  5. Add five Substring match blocks to your AutoTest configuration and nest them inside of the IO test block. Make sure each match block is case insensitive and ignores whitespace.

  6. Copy and paste the info from the table below into the Input and Expected output fields in their respective match block:

InputExpected output

1

1

3

1 1 2

5

1 1 2 3 5

0

invalid

-1

invalid

It's a good idea to give your tests descriptive names so that it's clear to both you and your students what is actually being checked (e.g. "Does your program produce the correct output? - Input: 5").

Step 4.3: Code structure tests

Semgrep is a code structure testing framework that is excellent for checking if students have used a specific syntax for reaching their solution. AutoTest v2 offers the Code structure test block and it's corresponding Positive match and Negative match blocks for running semgrep tests. For more information about these test blocks, see Create a Code Structure Test.

For this example we want to check that the students have used a while loop and an if-elif-else statement in their program. Here are the Semgrep rules we will be using:

rules:
  - id: untitled_rule
    pattern: |
      while $COND:
        ...
    message: Semgrep found a match
    languages: [python]
    severity: WARNING
rules:
  - id: untitled_rule
    pattern: |
      if $COND1:
        ...
      elif $COND2:
        ...
      else:
        ...
    message: Semgrep found a match
    languages: [python]
    severity: WARNING
  1. Add a Connect rubric block to your test configuration and select the "Code structure tests" rubric category.

  2. Add a Code structure test block to your test configuration and nest it within the Connect rubric block.

  3. In the Student file input field, write "fibonacci.py".

  4. Add two Positive match blocks to your test configuration and nest them within the Code structure test block

  5. Copy and paste the semgrep rules in the code blocks above into the provided editor in each Positive match block. Make sure to delete the template provided.

Step 4.4: Flake8 code quality tests

Flake8 is a code quality assessment tool (also known as a linter) for python that automatically generates comments on a script based on it's adherence to the PEP8 style guide for Python. The Flake8 block in AutoTest v2 is a great way to enforce industry standard coding practices with your students. For more information about the Flake8 block, see Create a Flake8 Test.

  1. Add a Connect rubric block to your test configuration and select the "Flake8 code quality tests" rubric category

  2. Add a Flake8 block to your test configuration and nest it within the Connect rubric block.

  3. In the Student file input field write "fibonacci.py"

Step 5: Test and publish your AutoTests

It's important to test your AutoTest configuration before running it on students' submissions to make sure that your tests are running as expected and to check for edge cases. This is easy to do with Snapshots. When you're ready to check your tests, simply press the Build snapshot button at the bottom of the test block sidebar. This will make a test run of your AutoTest configuration on your Test submission.

The first time you build a snapshot, CodeGrade will prompt you to upload a Test submission. Use the "Click here to upload files" option or drag-and-drop the fibonacci.py file that you downloaded at the beginning of this tutorial and click "Submit".

Once you're happy with your tests, you need to publish them to your students for them to run on their submissions. Publish your tests by building a snapshot and at the bottom of the pop-up modal click the Publish snapshot button. Once it is published, AutoTest V2 is available for students through the editor and on the submission page.

Conclusion

You have just built your first automatically graded assignment, ready for your students to begin submitting work!

This guide is designed to get you started with a completed assignment but doesn't go into explicit detail about all of the features CodeGrade has to offer. For more in-depth information about the product and the various workflows that you can achieve, see Learn more or reach out to our support team at support@codegrade.com.

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