NumPy Data type: format_parser() function

Last update on August 19 2022 21:50:38 (UTC/GMT +8 hours)

numpy.format_parser()function

The format_parser() function is used to convert formats, names, titles description to a dtype.

After constructing the format_parser object, the dtype attribute is the converted data-type: dtype = format_parser(formats, names, titles).dtype

Version: 1.15.0

Syntax:

class numpy.format_parser(formats, names, titles, aligned=False, byteorder=None)

Parameter:

Name	Description	Required / Optional
formats : str or list of str	The format description, either specified as a string with comma-separated format descriptions in the form 'f8, i4, a5', or a list of format description strings in the form ['f8', 'i4', 'a5'].	Required
names : str or list/tuple of str	The field names, either specified as a comma-separated string in the form 'col1, col2, col3', or as a list or tuple of strings in the form ['col1', 'col2', 'col3']. An empty list can be used, in that case default field names (‘f0’, ‘f1’, …) are used.	Optional
titles : sequence	Sequence of title strings. An empty list can be used to leave titles out.	Optional
aligned : bool,	If True, align the fields by padding as the C-compiler would. Default is False.	Optional
byteorder : str,	If specified, all the fields will be changed to the provided byte-order. Otherwise, the default byte-order is used.	Optional

Return value:

dtype : dtype or Python type - The data type of rep.

Example: numpy.format_parser() function

>>> import numpy as np
>>> np.format_parser(['f8', 'i4', 'a5'], ['col1', 'col2', 'col3'], ['T1', 'T2', 'T3']).dtype
dtype([(('T1', 'col1'), '<f8'), (('T2', 'col2'), '<i4'), (('T3', 'col3'), 'S5')])

Example: numpy.format_parser() function

>>> import numpy as np
>>> np.format_parser(['f8', 'i4', 'a5'], ['col1', 'col2', 'col3'], []).dtype
dtype([('col1', '<f8'), ('col2', '<i4'), ('col3', 'S5')])
>>> np.format_parser(['f8', 'i4', 'a5'], [], []).dtype
dtype([('f0', '<f8'), ('f1', '<i4'), ('f2', 'S5')])

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