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# numpy.nanprod

numpy.nanprod(a, axis=None, dtype=None, out=None, keepdims=<no value>, initial=<no value>, where=<no value>)

  Return the product of array elements over a given axis treating Not a Numbers (NaNs) as ones.

  One is returned for slices that are all-NaN or empty.

  Parameters:
    a array_like

      Array containing numbers whose product is desired. If a is not an array, a conversion is attempted.

    axis{int, tuple of int, None}, optional

      Axis or axes along which the product is computed. The default is to compute the product of the flattened array.

    dtype data-type, optional

      The type of the returned array and of the accumulator in which the elements are summed. By default, the dtype of a is used. An exception is when a has an integer type with less precision than the platform (u)intp. In that case, the default will be either (u)int32 or (u)int64 depending on whether the platform is 32 or 64 bits. For inexact inputs, dtype must be inexact.

    out ndarray, optional

      Alternate output array in which to place the result. The default is `None`. If provided, it must have the same shape as the expected output, but the type will be cast if necessary. See Output type determination for more details. The casting of NaN to integer can yield unexpected results.

    keepdims bool, optional

      If True, the axes which are reduced are left in the result as dimensions with size one. With this option, the result will broadcast correctly against the original arr.

    initial scalar, optional

      The starting value for this product. See `reduce` for details.

      Added in version 1.22.0.

    where array_like of bool, optional

      Elements to include in the product. See `reduce` for details.

      Added in version 1.22.0.

  Returns:
    nanprod ndarray

      A new array holding the result is returned unless out is specified, in which case it is returned.

  See also

  `numpy.prod`

    Product across array propagating NaNs.

  `isnan`

    Show which elements are NaN.

  Examples

      >>> import numpy as np
      >>> np.nanprod(1)
      1
      >>> np.nanprod([1])
      1
      >>> np.nanprod([1, np.nan])
      1.0
      >>> a = np.array([[1, 2], [3, np.nan]])
      >>> np.nanprod(a)
      6.0
      >>> np.nanprod(a, axis=0)
      array([3., 2.])