如何定义具有所有可能的数字组合的数组

def generate_combinations(length):
    # 初始化数字数组
    digits = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
    result = []

    # 递归生成组合
    def generate_helper(current, remaining):
        if len(current) == length:
            result.append(current)
            return
        for i in range(len(remaining)):
            generate_helper(current + [remaining[i]], remaining[:i] + remaining[i+1:])

    generate_helper([], digits)
    return result