|---| | [ View source on GitHub](https://github.com/tensorflow/tensorflow/blob/v2.15.1/tensorflow/python/ops/math_ops.py#L2570-L2643) | Computes number of nonzero elements across dimensions of a tensor. ```python tf.math.count_nonzero( input, axis=None, keepdims=None, dtype=`tf.dtypes.int64`, name=None ) ``` Reduces `input` along the dimensions given in `axis`. Unless `keepdims` is true, the rank of the tensor is reduced by 1 for each entry in `axis`. If `keepdims` is true, the reduced dimensions are retained with length 1. If `axis` has no entries, all dimensions are reduced, and a tensor with a single element is returned. > [!NOTE] > **Note:** Floating point comparison to zero is done by exact floating point equality check. Small values are **not** rounded to zero for purposes of the nonzero check. #### For example: ```python x = tf.constant([[0, 1, 0], [1, 1, 0]]) tf.math.count_nonzero(x) # 3 tf.math.count_nonzero(x, 0) # [1, 2, 0] tf.math.count_nonzero(x, 1) # [1, 2] tf.math.count_nonzero(x, 1, keepdims=True) # [[1], [2]] tf.math.count_nonzero(x, [0, 1]) # 3 ``` > [!NOTE] > **Note:** Strings are compared against zero-length empty string `""`. Any string with a size greater than zero is already considered as nonzero. #### For example: ```python x = tf.constant(["", "a", " ", "b", ""]) tf.math.count_nonzero(x) # 3, with "a", " ", and "b" as nonzero strings. ```


| ## Args || |---|---| | `input` | The tensor to reduce. Should be of numeric type, `bool`, or `string`. | | `axis` | The dimensions to reduce. If `None` (the default), reduces all dimensions. Must be in the range `[-rank(input), rank(input))`. | | `keepdims` | If true, retains reduced dimensions with length 1. | | `dtype` | The output dtype; defaults to [`tf.int64`](https://www.tensorflow.org/versions/r2.15/api_docs/python/tf.md.txt#int64). | | `name` | A name for the operation (optional). |



| ## Returns || |---|---| | The reduced tensor (number of nonzero values). ||