Can you change to numpy format for parameters? I think what I wrote below will cover it. Also, can you add an example in doctest form, just so the reader has an idea. I think we do this for all the read/write functions.

```
Parameters
---------------
dataframe: DataFrame
    DataFrame to be written
destination_table: string
     name of table to be written, in the form 'dataset.tablename'
schema : sequence (optional)
     list of column types in order for data to be inserted, e.g. ['INTEGER', 'TIMESTAMP', 'BOOLEAN']
col_order: sequence (optional)
     order which columns are to be inserted, e.g. ['primary_key', 'birthday', 'username']
if_exists: {'fail', 'replace', 'append'} (optional)
        fail: If table exists, do nothing.
        replace: If table exists, drop it, recreate it, and insert data.
        append: If table exists, insert data. Create if does not exist.
```