Not able to change format of cells to "NUMBER" or "SCIENTIFIC" using google sheets API

Question

I am using python Google Sheet APIs(Python) to change formats of a few columns from text to either scientific or number. However, when I run the below code, it finishes without any errors, but the columns specified in the range are still text. Am I missing something?

request = [{
        "repeatCell": {
        "range": {
            "sheetId": 0,
            "startRowIndex": 1,
            "endRowIndex": 100,
            "startColumnIndex": 5,
            "endColumnIndex": 16
        },
        "cell": {
            "userEnteredFormat": {
            "numberFormat": {
                "type": "SCIENTIFIC",
                "pattern": "0.00e+00"
            }
            }
        },
        "fields": "userEnteredFormat"
        }
    },
    {
        "repeatCell": {
        "range": {
            "sheetId": 0,
            "startRowIndex": 1,
            "endRowIndex": 100,
            "startColumnIndex": 3,
            "endColumnIndex": 4
        },
        "cell": {
            "userEnteredFormat": {
                "numberFormat": {
                    "type": "NUMBER",
                    "pattern": "#,##0.0000"
                }
            }
        },
        "fields": "userEnteredFormat"
        }
    }]

    body = {
        'requests': request
    }
    response = sheet_service.spreadsheets() \
        .batchUpdate(spreadsheetId=sumSheetId, body=body).execute()