问题描述:
Write a function to rotate a given list by specified number of items to the left direction.

测试用例:
['assert rotate_left([1, 2, 3, 4, 5, 6, 7, 8, 9, 10],3,4)==[4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4]', 'assert rotate_left([1, 2, 3, 4, 5, 6, 7, 8, 9, 10],2,2)==[3, 4, 5, 6, 7, 8, 9, 10, 1, 2]', 'assert rotate_left([1, 2, 3, 4, 5, 6, 7, 8, 9, 10],5,2)==[6, 7, 8, 9, 10, 1, 2]']

生成的代码:
def rotate_left(lst, start_index, num_rotations):
    n = len(lst)
    # Ensure starting index is within bounds
    start_index = start_index % n
    # Calculate effective rotations
    effective_rotations = (start_index + num_rotations) % n
    # Perform the rotation
    return lst[effective_rotations:] + lst[:effective_rotations]

# Test cases
assert rotate_left([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 3, 4) == [8, 9, 10, 1, 2, 3, 4, 5, 6, 7]
assert rotate_left([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 2, 2) == [5, 6, 7, 8, 9, 10, 1, 2]
assert rotate_left([1, 2, 3, 4, 5],5 ,2) == [3]