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Python Exercises

Python NumPy: Find unique rows in a numpy array

Python NumPy: Array Object Exercise-87 with Solution

Write a Python program to find unique rows in a numpy array.

Sample Solution:-

Python Code:

import numpy as np
x = np.array([[20, 20, 20, 0],
              [0, 20, 20, 20],
              [0, 20, 20, 20],
              [20, 20, 20, 0],
              [10, 20, 20,20]])
print("Original array:")
print(x)
y = np.ascontiguousarray(x).view(np.dtype((np.void, x.dtype.itemsize * x.shape[1])))
_, idx = np.unique(y, return_index=True)

unique_result = x[idx]
print("Unique rows of the above array:")
print(unique_result)

Sample Output:

Original array:                                                        
[[20 20 20  0]                                                         
 [ 0 20 20 20]                                                         
 [ 0 20 20 20]                                                         
 [20 20 20  0]                                                         
 [10 20 20 20]]                                                        
Unique rows of the above array:                                        
[[ 0 20 20 20]                                                         
 [10 20 20 20]                                                         
 [20 20 20  0]]

Python Code Editor:

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