NumPy 基本操作(np.where函数)

                                                                np.where函数

np.where函数:

    np.where 函数是三元表达式 x if condition else y 的矢量化版本。

    help(np.where):        

Help on built-in function where in module numpy:

where(...)
    where(condition, [x, y])
    
    Return elements chosen from `x` or `y` depending on `condition`.
    
    .. note::
        When only `condition` is provided, this function is a shorthand for
        ``np.asarray(condition).nonzero()``. Using `nonzero` directly should be
        preferred, as it behaves correctly for subclasses. The rest of this
        documentation covers only the case where all three arguments are
        provided.
    
    Parameters
    ----------
    condition : array_like, bool
        Where True, yield `x`, otherwise yield `y`.
    x, y : array_like
        Values