CODEWITHSUNDEEP
pythonarraysnumpy
Riggun
Riggun

Reputation: 315

Python quick search in numpy array

Does Numpy have a function for quick search of element in 2D array and return its indexes? Mean for example:

a=54
array([[ 0,  1,  2,  3],
      [ 4,  5,  54,  7],
      [ 8,  9, 10, 11]])

So equal value will be array[1][2]. Of course I can make it using simple loops- but I want something similar to: 

   if 54 in arr

Upvotes: 0

Views: 1827

Answers (1)

Akavall
Akavall

Reputation: 86168

In [4]: import numpy as np 

In [5]: my_array = np.array([[ 0,  1,  2,  3],
                             [ 4,  5,  54,  7],
                             [8, 54, 10, 54]])

In [6]: my_array
Out[6]: 
array([[ 0,  1,  2,  3],
       [ 4,  5, 54,  7],
       [ 8, 54, 10, 54]])

In [7]: np.where(my_array == 54) #indices of all elements equal to 54
Out[7]: (array([1, 2, 2]), array([2, 1, 3])) #(row_indices, col_indices)

In [10]: temp = np.where(my_array == 54)

In [11]: zip(temp[0], temp[1])   # maybe this format is what you want
Out[11]: [(1, 2), (2, 1), (2, 3)]

Upvotes: 3

Related Questions