  # numpy.sum () in Python

NumPy | Python Methods and Functions

` numpy.sum (arr, axis, dtype, out) `: This function returns the sum of the array elements along the specified axis.

Parameters:
arr: input array.
axis: axis along which we want to calculate the sum value. 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: Different array in which we want to place the result. The array must have same dimensions as expected output. Default is None.
initial: [scalar, optional] Starting value of the sum.

Return: Sum of the array elements ( a scalar value if axis is none) or array with sum values ​​along the specified axis.

Code # 1:

 ` # Python program illustrating ` ` # numpy.sum () method ` ` import ` ` numpy as np `   ` # 1D array ` ` arr ` ` = ` ` [` ` 20 ` `, ` ` 2 ` `,. ` ` 2 ` `, ` ` 10 ` `, ` ` 4 ` `] ` ` `  ` print ` ` (` ` "Sum of arr : "` `, np. ` ` sum ` ` (arr)) `   ` print ` ` (` ` "Sum of arr (uint8):" ` `, np. ` ` sum ` ` (arr, dtype ` ` = ` ` np.uint8)) ` ` print ` ` (` ` "Sum of arr (float32):" ` `, np. ` ` sum ` ` (arr, dtype ` ` = ` ` np.float32)) ` ` `  ` print ` ` (` `" Is np.sum (arr) .dtype == np.uint: "` `, ` ` ` ` np. ` ` sum ` ` (arr) .dtype ` ` = ` ` = ` ` np.uint) `   ` print ` ` (` ` "Is np.sum (arr) .dtype == np.uint:" ` `, ` ` np. ` ` sum ` ` (arr) .dtype ` ` = ` ` = ` ` np. ` ` float ) `

Output:

` Sum of arr: 36.2 Sum of arr (uint8): 36 Sum of arr (float32): 36.2 Is np.sum (arr) .dtype == np.uint : False Is np.sum (arr) .dtype == np.uint: True `

Code # 2:

 ` # Python program illustrating ` ` # numpy.sum () method ` ` import ` ` numpy as np `   ` # 2D array ` ` arr ` ` = ` ` [[` ` 14 ` `, ` ` 17 ` `, ` ` 12 ` `, ` ` 33 ` `, ` ` 44 ` `], < / code> `` [ 15 , 6 , 27 , 8 , 19 ],  [ 23 , 2 , 54 , 1 , 4 ,]]    print ( "Sum of arr:" , np. sum (arr))  < code class = "undefined spaces">   print ( " Sum of arr (uint8): " , np. sum (arr, dtype = np.uint8))  print ( "Sum of arr (float32):" , np. sum (arr, dtype = np.float32))   print ( " Is np.sum (arr) .dtype == np.uint: " ,  np. sum (arr) .dtype = = np.uint)    print ( "Is np.sum (arr) .dtype == np.uint:" ,    np. sum (arr) .dtype = = np. float ) `

Output:

` Sum of arr: 279 Sum of arr (uint8): 23 Sum of arr (float32): 279.0 Is np.sum (arr) .dtype == np.uint : False Is np.sum (arr) .dtype == np.uint: False `

Code # 3:

 ` # Python program illustrating ` ` # numpy.sum () method `   ` import ` ` numpy as np ` ` `  ` # 2D array ` ` arr ` ` = ` ` [[` ` 14 ` `, ` ` 17 ` `, ` ` 12 ` `, ` ` 33 ` `, ` ` 44 ` `] , ` ` [` ` 15 , 6 , 27 , 8 , 19 ], ``   [ 23 , 2 , 54 , 1 , 4 ,]]    print ( "Sum of arr:" , np. sum (arr))  print ( "Sum of arr (axis = 0):" , np. sum (arr, axis = 0 ))  print ( "Sum of arr (axis = 1):" , np. sum (arr, axis = 1 ))   print ( "Sum of arr (keepdimension is True):" ,   np. sum (arr, axis = 1 , keepdims = True )) `

Exit :

` Sum of arr: 279 Sum of arr (axis = 0) : [52 25 93 42 67] Sum of arr (axis = 1): [120 75 84] Sum of arr (keepdimension is True): [  ] `