NumPy: Remove the first dimension from a given array of shape (1,3,4)

NumPy: Array Object Exercise-195 with Solution

Write a NumPy program to remove the first dimension from a given array of shape (1,3,4).

Sample array:
[[[1, 2, 3, 4],
[0, 1, 3, 4],
[5, 0, 3, 2]]])

Sample Solution:

Python Code:

# Importing NumPy library
import numpy as np

# Creating a NumPy array with a shape of (1, 3, 4) containing nested lists
nums = np.array([[[1, 2, 3, 4],
                  [0, 1, 3, 4],
                  [5, 0, 3, 2]]])

# Printing the shape of the array
print('Shape of the said array:')
print(nums.shape)

# Removing the first dimension of the array's shape using slicing
# The result will have a shape of (3, 4)
result = nums[0]
print("\nAfter removing the first dimension of the shape of the said array:")
print(result.shape) 

Sample Output:

Shape of the said array:
(1, 3, 4)

After removing the first dimension of the shape of the said array:
(3, 4)

Explanation:

In the above exercise -

The NumPy code first creates a 3-dimensional array nums with shape (1, 3, 4).

print(nums.shape): The print() function prints the shape of the “nums” array.

new_array = np.squeeze(nums, axis=0): Here, the np.squeeze() function is used to remove the first dimension (axis=0) of the "nums" array. The result is assigned to the variable "new_array".

print(new_array.shape): Finally print() function prints the shape of the “new_array” which returns (3, 4).

Python-Numpy Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Write a NumPy program to create two arrays with shape (300,400, 5), fill values using unsigned integer (0 to 255). Insert a new axis that will appear at the beginning in the expanded array shape. Now combine the said two arrays into one.
Next: Write a NumPy program to create a 12x12x4 array with random values and extract any array of shape(6,6,3) from the said array.