You can find the index of an element in the NumPy array with the following code. I highly recommend you the “Python Crash Course Book” to learn Python. In this article, you’ll see the four examples with solutions. These examples are:
- Find the index of an element in a 1D NumPy array
- Index of the element in a 2D NumPy array
- Index based on multiple conditions
- The first index of an element in an array
Example 1: Index of an element in 1D Numpy array
# Import the NumPy library as np import numpy as np # Create a 1D NumPy array a = np.array([5, 10, 15, 20, 5, 10]) # Index of a value index = np.argwhere(a == 5) # Display the output print(index)
Output:
[[0] [4]]
Example 2: Index of an element in 2d array Python
# Import the NumPy library as np
import numpy as np
# Create a 2D NumPy array
a = np.array([[5, 10, 15, 20, 10],
[10, 20, 30, 40, 5]])
# Index of a value
index = np.argwhere(a == 10)
# Display the output
print(index)Output:
[[0 1] [0 4] [1 0]]
Example 3: Selection based on multiple conditions
# Import the NumPy library as np import numpy as np # Create a 1D NumPy array a = np.array([5, 10, 15, 20, 10, 30]) # Index of a value index = np.argwhere((a > 10) & (a < 20)) # Display the output print(index)
Output:
[[2]]
Example 4: First index of an element in an array
# Import the NumPy library as np
import numpy as np
# Create a 1D NumPy array
a = np.array([5, 10, 15, 20, 10, 30])
# Index of a value
index = np.argwhere(a == 10)
if len(index) > 0:
# Display the output
print(index[0][0])Output:
1
