`numpy:isscalar`

source: /numpy/_core/numeric.py :1975

Signature

def isscalar ( element )

Summary

Returns True if the type of element is a scalar type.

Parameters

element : any: Input argument, can be of any type and shape.

Returns

val : bool: True if element is a scalar type, False if it is not.

Notes

If you need a stricter way to identify a numerical scalar, use isinstance(x, numbers.Number), as that returns False for most non-numerical elements such as strings.

In most cases np.ndim(x) == 0 should be used instead of this function, as that will also return true for 0d arrays. This is how numpy overloads functions in the style of the dx arguments to gradient and the bins argument to histogram. Some key differences:

+------------------------------------+---------------+-------------------+
| x                                  |``isscalar(x)``|``np.ndim(x) == 0``|
+====================================+===============+===================+
| PEP 3141 numeric objects           | ``True``      | ``True``          |
| (including builtins)               |               |                   |
+------------------------------------+---------------+-------------------+
| builtin string and buffer objects  | ``True``      | ``True``          |
+------------------------------------+---------------+-------------------+
| other builtin objects, like        | ``False``     | ``True``          |
| `pathlib.Path`, `Exception`,       |               |                   |
| the result of `re.compile`         |               |                   |
+------------------------------------+---------------+-------------------+
| third-party objects like           | ``False``     | ``True``          |
| `matplotlib.figure.Figure`         |               |                   |
+------------------------------------+---------------+-------------------+
| zero-dimensional numpy arrays      | ``False``     | ``True``          |
+------------------------------------+---------------+-------------------+
| other numpy arrays                 | ``False``     | ``False``         |
+------------------------------------+---------------+-------------------+
| `list`, `tuple`, and other         | ``False``     | ``False``         |
| sequence objects                   |               |                   |
+------------------------------------+---------------+-------------------+

Examples

import numpy as np

✓

np.isscalar(3.1)

✓

np.isscalar(np.array(3.1))

✓

np.isscalar([3.1])

✓

np.isscalar(False)

✓

np.isscalar('numpy')

✓

NumPy supports PEP 3141 numbers:

from fractions import Fraction
np.isscalar(Fraction(5, 17))
from numbers import Number
np.isscalar(Number())

✓

Aliases

numpy.isscalar