w3resource

Pandas DataFrame: to_hdf() function

DataFrame - to_hdf() function

The to_hdf() function is used to write the contained data to an HDF5 file using HDFStore.

Syntax:

DataFrame.to_hdf(self, path_or_buf, key, **kwargs)

Parameters:

Name Description Type/Default Value Required / Optional
path_or_buf      File path or HDFStore object. str or pandas.HDFStore Required
key        Identifier for the group in the store. str Required
mode   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.
{'a', 'w', 'r+'}
Default Value: ‘a’
Required
format   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.
{‘fixed’, ‘table’}
Default Value: ‘fixed’
Required
append    For Table formats, append the input data to the existing. bool
Default Value: False
Required
data_columns   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.  list of columns
Default Value: True
Optional
complevel   Specifies a compression level for data. A value of 0 disables compression. {0-9} Optional
complib   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. {‘zlib’, ‘lzo’, ‘bzip2’, ‘blosc’}
Default Value: ‘zlib’
Required
fletcher32   If applying compression use the fletcher32 checksum. bool
Default Value: False
Required
dropna   If true, ALL nan rows will not be written to store. bool
Default Value: False
Required
errors   Specifies how encoding and decoding errors are to be handled. See the errors argument for open() for a full list of options. str
Default Value: ‘strict’
Optional

Example:


Download the Pandas DataFrame Notebooks from here.

Previous: DataFrame - to_csv() function
Next: DataFrame - to_sql() function



Become a Patron!

Follow us on Facebook and Twitter for latest update.

It will be nice if you may share this link in any developer community or anywhere else, from where other developers may find this content. Thanks.

https://w3resource.com/pandas/dataframe/dataframe-to_hdf.php