python bigquery api load_table_from_dataframe not uploading to partitioned table

the folowing function runs but when i check bigquery there is nothing there. I am using the $ decorator to add a specific date and i have waited to be sure the data has uploaded:

def write_truncate_table(client, table_id, df, schema=None):
    job_config = bigquery.LoadJobConfig(
        schema=schema,
        # to append use "WRITE_APPEND" or don't pass job_config at all (appending is default)
        write_disposition="WRITE_TRUNCATE",
    )
    job = client.load_table_from_dataframe(df, table_id, job_config=job_config)  # Make an API request
    return job.result()