Python小实验2—产生式系统实验

1、实验内容

设已知初始事实存放在综合数据库中:
该动物身上有:暗斑点，长脖子，长腿，奶，蹄·推理机构的工作过程:
( 1)从规则库中取出r，检查其前提是否可与综合数据库中的已知事实匹配。匹配失败则r不能被用于推理。然后取r,进行同样的工作。匹配成功则r,被执行·综合数据库:
该动物身上有:暗斑点，长脖子，长腿，奶，蹄，哺乳动物
(2）分别用r，r4，rs，r,综合数据库中的已知事实进行匹配，均不成功。r,匹配成功，执行r,。
综合数据库:
该动物身上有:暗斑点，长脖子，长腿，奶，蹄，哺乳动物，有蹄类动物
( 3) r.匹配成功，并推出“该动物是长颈鹿”。

2、实验目的

1.建立规则库;
2.实现推理，打印推理过程，可文字或画图;
例如：
输入:该动物身上有:暗斑点，长脖子，长腿，奶，蹄输出:前提条件为:
有斑点长脖长腿蹄类产奶
推理过程如下:
产奶->哺乳类
有斑点，有黑色条纹，长脖，蹄类->长颈鹿
所识别的动物为长颈鹿

3、实验思路

1.实验先创建了一个特征数组characteristic ，将特征放进特征数组，方便后面提取特征时对比。
2.定义了一个bf算法BF(s, t)对比特征，可以从一句话里面提取有用的特征。
3.定义了一个描述数组describe 用来存放第二步提取的特征。
4.定义了一个特征搜索函数search(describe)，里面包含推理的过程，如果满足某一条条件，就会打印出来。而且在推理过程里面有总结某一个新的特征，也会加到描述数组里面去。
5.最后定义了一个输出结果函数result(describe) 判断最终结果有没有要查找的七种动物，如果有就输出动物名字，没有就输出无法判断是什么动物。

4、源代码

# 特征数组
characteristic = ["毛发","奶","羽毛","会飞","吃肉","犬齿","有爪","眼盯前方","有蹄",
                  "反刍动物","哺乳动物","鸟","善飞","信天翁","食肉动物","黄褐色","暗斑点",
                  "黑色条纹","长腿","长脖子","有蹄类动物","虎","金钱豹","长颈鹿","斑马",
                  "不会飞","黑白二色","会游泳","鸵鸟","企鹅","下蛋"]

# 描述数组
describe = []

def BF(s, t):
    i = 0
    j = 0
    k = 0
    flag = -1
    while (i < len(s) and j < len(t)):

        # 匹配成功
        if (i - k == j) and (j == len(t) - 1) and (s[i] == t[j]):
            flag = k
            break
        # s和t相等就继续向后匹配
        if s[i] == t[j]:
            i = i + 1
            j = j + 1

        # 不相等从k的位置开始匹配
        else:
            k = k + 1
            i = k
            j = 0
            # 假如s中所剩字符小于t中所剩字符
            if (len(s) - i) < len(t):
                flag = -1
                break

    return flag


print("请输入描述语句：")
S = input()

for i in range(len(characteristic)):
    if(BF(S,characteristic[i])!=-1):
        describe.append(characteristic[i])

def search(describe):
    for i in range(len(describe)):
        if(describe[i]=="毛发" or describe[i]=="奶"):
            print(describe[i]+"-->"+"哺乳动物")
            if("哺乳动物" not in describe):
                describe.append("哺乳动物")

        if(describe[i]=="羽毛"):
            print(describe[i]+"-->"+"鸟")
            if("鸟" not in describe):
                describe.append("鸟")

        if(describe[i] == "吃肉"):
            print(describe[i]+"-->"+"食肉动物")
            if ("食肉动物" not in describe):
                describe.append("食肉动物")

    if("会飞" in describe and "下蛋" in describe):
        print("会飞，下蛋--->鸟")
        if("鸟" not in describe):
            describe.append("鸟")

    if("犬齿" in describe and "有爪" in describe and "眼盯前方" in describe):
        print("犬齿，有爪，眼盯前方--->食肉动物")
        if("食肉动物" not in describe):
            describe.append("食肉动物")

    if("哺乳动物" in describe and "有蹄" in describe):
        print("哺乳动物，有蹄--->有蹄类动物")
        if("有蹄类动物" not in describe):
            describe.append("有蹄类动物")

    if("哺乳动物" in describe and "反刍动物" in describe):
        print("哺乳动物，反刍动物--->有蹄类动物")
        if("有蹄类动物" not in describe):
            describe.append("有蹄类动物")

    if("哺乳动物" in describe and "黄褐色" in describe and "食肉动物" in describe):
        if("暗斑点" in describe):
            print("哺乳动物，食肉动物，黄褐色，暗斑点--->金钱豹")
            if("金钱豹" not in describe):
                describe.append("金钱豹")
        if ("黑色条纹" in describe):
            print("哺乳动物，食肉动物，黄褐色，黑色条纹--->金钱豹")
            if ("虎" not in describe):
                describe.append("虎")

    if("有蹄类动物" in describe and "长脖子" in describe and "长腿" in describe and "暗斑点" in describe):
        print("有蹄类动物，长脖子，长腿，暗斑点--->长颈鹿")
        if("长颈鹿" not in describe):
            describe.append("长颈鹿")

    if("有蹄类动物" in describe and "黑色条纹" in describe):
        print("有蹄类动物，黑色条纹--->斑马")
        if("斑马" not in describe):
            describe.append("斑马")

    if ("鸟" in describe and "长脖子" in describe and "长腿" in describe and "不会飞" in describe and "黑白二色" in describe):
        print("鸟，长脖子,长腿,不会飞，黑白二色--->鸵鸟")
        if ("鸵鸟" not in describe):
            describe.append("鸵鸟")

    if ("鸟" in describe and "会游泳" in describe  and "不会飞" in describe and "黑白二色" in describe):
        print("鸟，会游泳，不会飞，黑白二色--->企鹅")
        if ("企鹅" not in describe):
            describe.append("企鹅")

    if("鸟" in describe and "善飞" in describe):
        print("鸟，善飞--->信天翁")
        if("信天翁" not in describe):
            describe.append("信天翁")

def result(describe):
    for i in range(len(describe)):
        if(describe[i]=="虎" or describe[i]=="金钱豹" or describe[i]=="斑马"
            or describe[i]=="长颈鹿" or describe[i]=="鸵鸟" or describe[i]=="企鹅" or describe[i]=="信天翁"):
            print("该动物是："+describe[i])

    if("虎" not in describe and "金钱豹" not in describe and "斑马" not in describe
            and "长颈鹿" not in describe and "鸵鸟" not in describe
            and "企鹅" not in describe and "信天翁" not in describe):
        print("无法判断是什么动物！")

print()
print("提取或者总结的特征：")
print(describe)
print()
print("推理过程：")
search(describe)
print()
print("结论：")
result(describe)

5、实验结果