How to send an array using requests.post (Python)? “Value Error: Too many values to unpack”

You want to pass in JSON encoded data. See the API documentation:

Remember — All post bodies must be JSON encoded data (no form data).

The requests library makes this trivially easy:

headers = {"W-Token": "Ilovemyboss"}
data = [
    {
        'url': '/rest/shifts',
        'params': {'user_id': 0, 'other_stuff': 'value'},
        'method': 'post',
    },
    {
        'url': '/rest/shifts',
        'params': {'user_id': 1,'other_stuff': 'value'},
        'method':'post',
    },
]
requests.post(url, json=data, headers=headers)

By using the json keyword argument the data is encoded to JSON for you, and the Content-Type header is set to application/json.