create_table

ketos.data_handling.database_interface.create_table(h5file, path, name, description, data_name='data', chunkshape=None, verbose=False)[source]

Create a new table.

If the table already exists, open it.

Args:

h5file: tables.file.File object: HDF5 file handler.
path: str: The group where the table will be located. Ex: ‘/features/spectrograms’
name: str: The name of the table.
table_description: class (tables.IsDescription): The class describing the table structure.
data_name: str or list(str): Name(s) of the table column(s) used to store the data array(s).
chunkshape: tuple: The chunk shape to be used for compression

Returns:

table: table.Table object: The created/open table.

Examples:

>>> import tables
>>> from ketos.data_handling.database_interface import open_file, table_description, create_table
>>> # Open a connection to the database
>>> h5file = open_file("ketos/tests/assets/tmp/database1.h5", 'w')
>>> # Create table descriptions for weakly labeled spectrograms with shape (32,64)
>>> descr = table_description((32,64), include_label=False)
>>> # Create 'table_data' within 'group1'
>>> my_table = create_table(h5file, "/group1/", "table_data", descr) 
>>> # Show the table description, with the field names (columns)
>>> # and information about types and shapes
>>> my_table
/group1/table_data (Table(0,)fletcher32, shuffle, zlib(1)) ''
  description := {
  "data": Float32Col(shape=(32, 64), dflt=0.0, pos=0),
  "filename": StringCol(itemsize=100, shape=(), dflt=b'', pos=1),
  "id": UInt32Col(shape=(), dflt=0, pos=2),
  "offset": Float64Col(shape=(), dflt=0.0, pos=3)}
  byteorder := 'little'
  chunkshape := (15,)
>>> # Close the HDF5 database file
>>> h5file.close()            