How do I use rsplit when adding a Requests response to python dictionary?

I am currently writing a script to scrape data from an API into a Python dictionary and then export the result into a JSON file. I am trying to get the file extension from a response by splitting using .rsplit('.', 1)[-1] The only problem is that some keys have ‘None" as their value and this throws the AttributeError: ‘NoneType’ object has no attribute ‘rsplit’. Here is my code snippet:

d = requests.get(dataset_url)

output = d.json()

output_dict = {
    'data_files': {
        # Format to get only extension
        'format': output.get('connectionParameters', {}).get('url').rsplit('.', 1)[-1],
        'url': output.get('connectionParameters', {}).get('url'),
    },
}

An example of JSON response with the required key is as follows:

"connectionParameters": {
    "csv_escape_char": "\\",
    "protocol": "DwC",
    "automation": false,
    "strip": false,
    "csv_eol": "\\n",
    "csv_text_enclosure": "\"",
    "csv_delimiter": "\\t",
    "incremental": false,
    "url": "https://registry.nbnatlas.org/upload/1564481725489/London_churchyards_dwc.txt",
    "termsForUniqueKey": [
      "occurrenceID"
    ]
  },

Any way to tackle this?

>Solution :

Try:

url = output.get("connectionParameters", {}).get("url") or "-"
f = url.rsplit(".", 1)[-1]

output_dict = {
    "data_files": {
        "format": f,
        "url": url,
    },
}

This will print:

{'data_files': {'format': '-', 'url': '-'}}

If the "url" parameter is None.