Parameters:

• path_or_buf: str or pandas.HDFStore – File path or HDFStore object.
• key: str – An identifier for the group in the store.
• mode: {‘a’, ‘w’, ‘r+’}, default ‘a’ – 

  Mode to open file:

  • ‘w’: write, a new file is created (an existing file with the same name would be deleted).

  • ‘a’: append, an existing file is opened for reading and writing, and if the file does not exist it is created.

  • ‘r+’: similar to ‘a’, but the file must already exist.

• complevel: {0-9}, default None – Specifies a compression level for data. A value of 0 or None disables compression.
• complib: {‘zlib’, ‘lzo’, ‘bzip2’, ‘blosc’}, default ‘zlib’ – Specifies the compression library to be used. As of v0.20.2 these additional compressors for Blosc are supported (default if no compressor specified: ‘blosc:blosclz’): {‘blosc:blosclz’, ‘blosc:lz4’, ‘blosc:lz4hc’, ‘blosc:snappy’, ‘blosc:zlib’, ‘blosc:zstd’}. Specifying a compression library which is not available issues a ValueError.
• append: bool, default False – For Table formats, append the input data to the existing.
• format: {‘fixed’, ‘table’, None}, default ‘fixed’:

  Possible values:

  • ‘fixed’: Fixed format. Fast writing/reading. Not-appendable, nor searchable.

  • ‘table’: Table format. Write as a PyTables Table structure which may perform worse but allow more flexible operations like searching / selecting subsets of the data.

  • If None, pd.get_option(‘io.hdf.default_format’) is checked, followed by fallback to “fixed”.

• index: bool, default True – Write DataFrame index as a column.
• min_itemsize: dict or int, optional – Map column names to minimum string sizes for columns.
• nan_rep: Any, optional – How to represent null values as str. Not allowed with append=True.
• dropna: bool, default False, optional – Remove missing values.
• data_columns: list of columns or True, optional – List of columns to create as indexed data columns for on-disk queries, or True to use all columns. By default only the axes of the object are indexed. See Query via data columns. for more information. Applicable only to format=’table’.
• errors: str, default ‘strict’ – Specifies how encoding and decoding errors are to be handled. See the errors argument for open() for a full list of options.
• encoding: str, default “UTF-8”