Python | Find elements within range in numpy

Given numpy array, the task is to find elements within some specific range. Let’s discuss some ways to do the task.

Method #1: Using np.where()

# python code to demonstrate
# finding elements in range
# in numpy array
import numpy as np

ini_array = np.array([1, 2, 3, 45, 4, 7, 810, 9, 6])

# printing initial array
print("initial_array : ", str(ini_array));

# find elements in range 6 to 10
result = np.where(np.logical_and(ini_array>= 6, ini_array<= 10))

# printing result
print("resultant_array : ", result)

Output:

initial_array :  [  1   2   3  45   4   7 810   9   6]
resultant_array :  (array([5, 7, 8]),)

Method #2: Using numpy.searchsorted()

# Python code to demonstrate
# finding elements in range
# in numpy array

import numpy as np

ini_array = np.array([1, 2, 3, 45, 4, 7, 9, 6])

# printing initial array
print("initial_array : ", str(ini_array));


# find elements in range 6 to 10
start = np.searchsorted(ini_array, 6, 'left')
end = np.searchsorted(ini_array, 10, 'right')
result = np.arange(start, end)

# printing result
print("resultant_array : ", result)

Output:

initial_array :  [ 1  2  3 45  4  7  9  6]
resultant_array :  [5 6 7]

Method #3: Using *

# Python code to demonstrate
# finding elements in range
# in numpy array

import numpy as np

ini_array = np.array([1, 2, 3, 45, 4, 7, 9, 6])

# printing initial array
print("initial_array : ", str(ini_array));


# find elements in range 6 to 10
result = ini_array[(ini_array>6)*(ini_array<10)]

# printing result
print("resultant_array : ", result)

Output:

initial_array :  [ 1  2  3 45  4  7  9  6]
resultant_array :  [7 9]