基于CanvasAPI开发作业自动评分脚本时的Python嵌套字典语法问题

Hey there! Let's sort out that syntax issue you're hitting with the CanvasAPI Python wrapper. The problem comes down to how you're structuring the nested dictionaries for the rubric_assessment parameter—your previous attempts aren't following Python's dictionary rules correctly.

Why Your Previous Attempts Failed #

Let's break down the errors:

• First attempt: You tried passing two separate dictionaries inside rubric_assessment, which isn't valid Python syntax. Dictionaries require key: value pairs, not just a list of unkeyed dictionaries.

  # Invalid: Multiple unkeyed dictionaries inside rubric_assessment
  edit(rubric_assessment={'criterion_#':{'points': 'point #'}, {'criterion_#':{'comments': 'comment_text'}}})
  

• Second attempt: You tried placing two dictionaries side-by-side without a shared parent key, which also violates dictionary structure rules. Python can't interpret unkeyed entries in a dictionary.

  # Invalid: Unkeyed sub-dictionary inside the parent dictionary
  edit(rubric_assessment={'criterion_#':{'points': 'point #'},{'comments': 'comment_text'}})
  

Correct Syntax Structure #

The Canvas API's rubric_assessment[criterion_id][points] and rubric_assessment[criterion_id][comments] map directly to a nested Python dictionary where:

1. The top-level rubric_assessment is a dictionary passed as a keyword argument to edit().
2. Inside it, each criterion_id acts as a key, and its value is another dictionary containing both points and comments keys (with your desired values).

Here's the correct single-criterion example:

edit(rubric_assessment={
    'criterion_#': {
        'points': 'point #',  # Replace with your actual point value
        'comments': 'comment_text'  # Replace with your feedback text
    }
})

If you need to submit assessments for multiple criteria, extend the top-level dictionary with additional criterion IDs and their nested data:

edit(rubric_assessment={
    'criterion_1': {
        'points': '10',
        'comments': 'Excellent grasp of the core concepts!'
    },
    'criterion_2': {
        'points': '8',
        'comments': 'Solid effort, but you missed a key detail in your explanation.'
    }
})

This structure perfectly aligns with what the Canvas API expects. The Python wrapper will automatically convert this nested dictionary into the proper API request format behind the scenes.

内容的提问来源于stack exchange，提问作者Daniel Hutchinson