'The DeleteDBInstance action deletes a previously provisioned
DB instance. A successful response from the web service
indicates the request was received correctly. When you delete
a DB instance, all automated backups for that instance are
deleted and cannot be recovered. Manual DB snapshots of the DB
instance to be deleted are not deleted.
If a final DB snapshot is requested the status of the RDS
instance will be "deleting" until the DB snapshot is created.
The API action `DescribeDBInstance` is used to monitor the
status of this operation. The action cannot be canceled or
reverted once submitted.
:type db_instance_identifier: string
:param db_instance_identifier:
The DB instance identifier for the DB instance to be deleted. This
parameter isn\'t case sensitive.
Constraints:
+ Must contain from 1 to 63 alphanumeric characters or hyphens
+ First character must be a letter
+ Cannot end with a hyphen or contain two consecutive hyphens
:type skip_final_snapshot: boolean
:param skip_final_snapshot: Determines whether a final DB snapshot is
created before the DB instance is deleted. If `True` is specified,
no DBSnapshot is created. If false is specified, a DB snapshot is
created before the DB instance is deleted.
The FinalDBSnapshotIdentifier parameter must be specified if
SkipFinalSnapshot is `False`.
Default: `False`
:type final_db_snapshot_identifier: string
:param final_db_snapshot_identifier:
The DBSnapshotIdentifier of the new DBSnapshot created when
SkipFinalSnapshot is set to `False`.
Specifying this parameter and also setting the SkipFinalShapshot
parameter to true results in an error.
Constraints:
+ Must be 1 to 255 alphanumeric characters
+ First character must be a letter
+ Cannot end with a hyphen or contain two consecutive hyphens'

def delete_db_instance(self, db_instance_identifier, skip_final_snapshot=None, final_db_snapshot_identifier=None):

    params = {'DBInstanceIdentifier': db_instance_identifier}
    if (skip_final_snapshot is not None):
        params['SkipFinalSnapshot'] = str(skip_final_snapshot).lower()
    if (final_db_snapshot_identifier is not None):
        params['FinalDBSnapshotIdentifier'] = final_db_snapshot_identifier
    return self._make_request(action='DeleteDBInstance', verb='POST', path='/', params=params)
