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

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]
``````

This method uses slice notation