taFrame object to file.
    Series.to_pickle : Pickle (serialize) Series object to file.
    read_hdf : Read HDF5 file into a DataFrame.
    read_sql : Read SQL query or database table into a DataFrame.
    read_parquet : Load a parquet object, returning a DataFrame.

    Notes
    -----
    read_pickle is only guaranteed to be backwards compatible to pandas 0.20.3
    provided the object was serialized with to_pickle.

    Examples
    --------
    >>> original_df = pd.DataFrame(
    ...     {{"foo": range(5), "bar": range(5, 10)}}
    ...    )  # doctest: +SKIP
    >>> original_df  # doctest: +SKIP
       foo  bar
    0    0    5
    1    1    6
    2    2    7
    3    3    8
    4    4    9
    >>> pd.to_pickle(original_df, "./dummy.pkl")  # doctest: +SKIP

    >>> unpickled_df = pd.read_pickle("./dummy.pkl")  # doctest: +SKIP
    >>> unpickled_df  # doctest: +SKIP
       foo  bar
    0    0    5
    1    1    6
    2    2    7
    3    3    8
    4    4    9
    