Function isscalar

numpy/_core/numeric.py:1911–1994

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. See Also -------- n

(element)

@set_module('numpy')
def isscalar(element):
    """
    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.

    See Also
    --------
    ndim : Get the number of dimensions of an array

    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)
    True