NumPy: decode() function

Last update on May 28 2022 11:21:48 (UTC/GMT +8 hours)

numpy.core.defchararray.decode() function

Calls str.decode element-wise.
The set of available codecs comes from the Python standard library, and may be extended at runtime.

Version: 1.15.0

Syntax:

numpy.core.defchararray.decode(a, encoding=None, errors=None)

Parameter:

Name	Description	Required / Optional
a: array_like of str or unicode		Required
encoding: str	The name of an encoding.	Optional
errors: str	Specifies how to handle encoding errors.	Optional

Return value:

out : ndarray

Note:

The 'chararray' class exists for backwards compatibility with Numarray, it is not recommended for new development. Starting from numpy 1.4, if one needs arrays of strings, it is recommended to use arrays of 'dtype' 'object_', 'string_' or 'unicode_', and use the free functions in the 'numpy.char' module for fast vectorized string operations.

Some methods will only be available if the corresponding string method is available in your version of Python.

The preferred alias for 'defchararray' is 'numpy.char'.

Example-1: numpy.char.decode() function

import numpy as np
x = np.array(['aAaAaA', '  aA  ', 'abBABba'])
print("x:", x)
e = np.char.encode(x, encoding='cp037')
print("\nAfter encoding: ", e)
d = np.char.decode(e, encoding='cp037')
print("\nAfter decodeing: ", d)

Output:

x: ['aAaAaA' '  aA  ' 'abBABba']

After encoding:  [b'\x81\xc1\x81\xc1\x81\xc1' b'@@\x81\[email protected]@'
 b'\x81\x82\xc2\xc1\xc2\x82\x81']

After decodeing:  ['aAaAaA' '  aA  ' 'abBABba']

Notes: The type of the result will depend on the encoding specified.

Example-2: numpy.char.decode() function

>>> import numpy as np
>>> a = np.char.encode('w3resource', 'cp500')
>>> b = np.char.decode(a,'cp500')
>>> b
array('w3resource', dtype='<U10')
>>> a
array(b'\xa6\xf3\x99\x85\xa2\x96\xa4\x99\x83\x85', dtype='|S10')

Python - NumPy Code Editor:

Previous: center()
Next: encode()