Python program that uses the deque class from the collections module to left rotate the elements of an array:

from collections import deque

def left_rotate(arr, n):
    # Create a deque from the array
    d = deque(arr)
    # Rotate the deque to the left
    d.rotate(-n)
    # Convert the deque back to a list
    return list(d)

# Example usage
arr = [1, 2, 3, 4, 5]
n = 2
print(left_rotate(arr, n))

The function left_rotate(arr, n) takes an array arr and an integer n as arguments. It first creates a deque object d from the array arr using the deque() constructor from the collections module. Then, it uses the rotate() method to rotate the deque to the left by n positions. The rotate() method takes an integer as an argument, a positive value rotates the elements to the right and a negative value rotates the elements to the left. Finally, it converts the deque back to a list and returns it.

The example usage creates an array arr and an integer n and calls the left_rotate() function to left rotate the elements of the array arr by n positions, and then it prints the resulting list.

You could also use slice notation with concatenation to left rotate the elements of an array.

def left_rotate(arr, n):
    return arr[n:] + arr[:n]