# numpy.mean() in Python

`numpy.mean(arr, axis = None)` : Compute the arithmetic mean (average) of the given data (array elements) along the specified axis.
Parameters : arr : [array_like]input array. axis : [int or tuples of int]axis along which we want to calculate the arithmetic mean. Otherwise, it will consider arr to be flattened(works on all the axis). axis = 0 means along the column and axis = 1 means working along the row. out : [ndarray, optional]Different array in which we want to place the result. The array must have the same dimensions as expected output. dtype : [data-type, optional]Type we desire while computing mean. Results : Arithmetic mean of the array (a scalar value if axis is none) or array with mean values along specified axis.
Code #1:
 `# Python Program illustrating  ``# numpy.mean() method  ``import` `numpy as np ``   ` `# 1D array  ``arr ``=` `[``20``, ``2``, ``7``, ``1``, ``34``] `` ` `print``(``"arr : "``, arr)  ``print``(``"mean of arr : "``, np.mean(arr)) ``  `

Output :
```arr :  [20, 2, 7, 1, 34]
mean of arr :  12.8
```
Code #2:
 `# Python Program illustrating  ``# numpy.mean() method    ``import` `numpy as np ``   ` ` ` `# 2D array  ``arr ``=` `[[``14``, ``17``, ``12``, ``33``, ``44``],   ``       ``[``15``, ``6``, ``27``, ``8``, ``19``],  ``       ``[``23``, ``2``, ``54``, ``1``, ``4``, ]]  ``   ` `# mean of the flattened array  ``print``(``"\nmean of arr, axis = None : "``, np.mean(arr))  ``   ` `# mean along the axis = 0  ``print``(``"\nmean of arr, axis = 0 : "``, np.mean(arr, axis ``=` `0``))  ``  ` `# mean along the axis = 1  ``print``(``"\nmean of arr, axis = 1 : "``, np.mean(arr, axis ``=` `1``)) `` ` `out_arr ``=` `np.arange(``3``) ``print``(``"\nout_arr : "``, out_arr)  ``print``(``"mean of arr, axis = 1 : "``,  ``      ``np.mean(arr, axis ``=` `1``, out ``=` `out_arr)) `

Output :
```mean of arr, axis = None :  18.6

mean of arr, axis = 0 :  [17.33333333  8.33333333 31.         14.         22.33333333]

mean of arr, axis = 1 :  [24.  15.  16.8]

out_arr :  [0 1 2]
mean of arr, axis = 1 :  [24 15 16]
```

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