Python/Json:Expecting property name enclosed in double quotes

This:

{
    'http://example.org/about': {
        'http://purl.org/dc/terms/title': [
            {'type': 'literal', 'value': "Anna's Homepage"}
        ]
     }
}

is not JSON.
This:

{
     "http://example.org/about": {
         "http://purl.org/dc/terms/title": [
             {"type": "literal", "value": "Anna's Homepage"}
          ]
      }
}

is JSON.

EDIT:
Some commenters suggested that the above is not enough.
JSON specification – RFC7159 states that a string begins and ends with quotation mark. That is ".
Single quoute ' has no semantic meaning in JSON and is allowed only inside a string.