index_key (string) – The key to use as indexing in the output dataframe
keys (dict, optional) – A dictionary that maps keys in the cdf file to the corresponding
desired keys in the ouput dataframe. If a particular cdf key has
multiple columns, the mapped keys must be in a list.
dtimeindex (bool, optional) – If True, DataFrame index is parsed as a datetime.
Default is True.
badvalues (dict, list, optional) – A dictionary that maps the new DataFrame column keys to a list of bad
values to replace with nans. Alternatively a list of numbers which are
replaced with nans in all columns.