I have minor doubts about this particular pattern, but not a showstopper. Changes will be accepted, and I encourage you to contribute an additional change with the following.

To be clear, this code does work as intended, even in a case where it doesn't seem like it should. For instance, if package_update_details is an immutable sequence, like a tuple, one might think it can't be updated. In fact, the dicts contained in the sequence can be updated, and the tuple that points to them is not being changed. Though this works, I would like to see it cleaned up so that we aren't changing an object as we iterate through it.

Further, if the detail inside the loop is not a dict, it will throw TypeError: string indices must be integers when trying to access one of its keys. That's not a clear error message for what actually happened, so I would like to see that error handled in a way that contextualizes the problem for the end user. For example:

if not isinstance(detail, dict):
    raise ValueError("Package details must be a list of dicts, each with required keys `amazon_order_id`, `package_id`, and `slot_id` (optional keys: `slot_start_time` and `slot_end_time`)")

Similarly, detail.pop('amazon_order_id') will throw KeyError: 'amazon_order_id' if that key is missing. Again, in context, this is a bit obscure, and we want the user to see some more details to help them out. Ideally, the dict should be tested for those required keys, with the same ValueError as above thrown if any are missing, so that the developer knows what went wrong more quickly.

These concerns can be handled by a utility function from elsewhere in the module.

@GriceTurrble thanks for pointing this out. I will fix these points. The package_update_details won't be modified in the function. And the function will throw an error if a non dict or a dict without required keys is passed.