参考知乎答案：手机的九宫格图案解锁总共能绘出多少种图案？ - linkwun 的回答 - 知乎

impossible = {13: 2,
              46: 5,
              79: 8,
              17: 4,
              28: 5,
              39: 6,
              19: 5,
              37: 5,
              31: 2,
              64: 5,
              97: 8,
              71: 4,
              82: 5,
              93: 6,
              91: 5,
              73: 5,
              }

def func(n):
    if not 1 <= n <= 9:
        raise ValueError("1 <= n <= 9")
    numbers = list(range(1, 10))
    result = []
    num = random.choice(numbers)
    result.append(num)
    numbers.remove(num)
    for i in range(n-1):
        next_numbers = numbers[:]
        for next_num in next_numbers[:]:
            key = result[-1]*10 + next_num
            if key in impossible:
                if impossible[key] not in result:
                    next_numbers.remove(next_num)
        num = random.choice(next_numbers)
        result.append(num)
        numbers.remove(num)
    return result

大小写不敏感，忽略空格下划线
http://robotframework.org/robotframework/latest/RobotFrameworkUserGuide.html#keyword-names