python之面向对象

class ():
    def __init__(self,title,author,context):
        print("init function called")
        self.title=title
        self.auther=auther
        self.__context=context   
        
    def get_context_length(self):
        return  len(self.__context)
    
    def intercept_context(self,length):
        self.__context=self.__context[:length]

harry_potter_book=Document('Harry potter','J.K.Rowling', '... Forever Do not believe any thing is capable of thinking independently ...')


print(harry_potter_book.title)
print(harry_potter_book.author)
print(harry_potter_book.get_context_length())

harry_potter_book.intercept_context(10)

print(harry_potter_book.get_context_length())

print(harry_potter_book.__context)

########## 输出 ##########

init function called
Harry Potter
J. K. Rowling
77
10

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-5-b4d048d75003> in <module>()
     22 print(harry_potter_book.get_context_length())
     23 
---> 24 print(harry_potter_book.__context)

AttributeError: 'Document' object has no attribute '__context'

class ():
    WELCOME_STR='Welcome! The context for this book is {}'
    
    def __init__(self):
        print('init function called')
        self.title=title
        self.author=author
        self.__context=context
        

    def create_empty_book(cls,title,author):
        return cls(title=title,author=author,context='nothing')
    
    #成员函数
    def get_context_legth(self):
        return len(self.__context)
    
    @staticmethod   #静态函数
    def get_welcome(context):
        return Document.WELCOME_STR.format(context)

empty_book = Document.create_empty_book('What Every Man Thinks About Apart from Sex', 'Professor Sheridan Simove')


print(empty_book.get_context_length())
print(empty_book.get_welcome('indeed nothing'))

########## 输出 ##########

init function called
7
Welcome! The context for this book is indeed nothing.

class Entity():
    def __init__(self, object_type):
        print('parent class init called')
        self.object_type = object_type
    
    def get_context_length(self):
        raise Exception('get_context_length not implemented')
    
    def print_title(self):
        print(self.title)

class (Entity):
    def __init__(self, title, author, context):
        print('Document class init called')
        Entity.__init__(self, 'document')
        self.title = title
        self.author = author
        self.__context = context
    
    def get_context_length(self):
        return len(self.__context)
    
class Video(Entity):
    def __init__(self, title, author, video_length):
        print('Video class init called')
        Entity.__init__(self, 'video')
        self.title = title
        self.author = author
        self.__video_length = video_length
    
    def get_context_length(self):
        return self.__video_length

harry_potter_book = Document('Harry Potter(Book)', 'J. K. Rowling', '... Forever Do not believe any thing is capable of thinking independently ...')
harry_potter_movie = Video('Harry Potter(Movie)', 'J. K. Rowling', 120)

print(harry_potter_book.object_type)
print(harry_potter_movie.object_type)

harry_potter_book.print_title()
harry_potter_movie.print_title()

print(harry_potter_book.get_context_length())
print(harry_potter_movie.get_context_length())

########## 输出 ##########

Document class init called
parent class init called
Video class init called
parent class init called
document
video
Harry Potter(Book)
Harry Potter(Movie)
77
120

from abc import ABCMeta, abstractmethod

class Entity(metaclass=ABCMeta):
    @abstractmethod
    def get_title(self):
        pass

    @abstractmethod
    def set_title(self, title):
        pass

class (Entity):
    def get_title(self):
        return self.title
    
    def set_title(self, title):
        self.title = title

document = Document()
document.set_title('Harry Potter')
print(document.get_title())

entity = Entity()

########## 输出 ##########

Harry Potter

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-7-266b2aa47bad> in <module>()
     21 print(document.get_title())
     22 
---> 23 entity = Entity()
     24 entity.set_title('Test')

TypeError: Can't instantiate abstract class Entity with abstract methods get_title, set_title

# 1.txt
I have a dream that my four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character. I have a dream today.

# 2.txt
I have a dream that one day down in Alabama, with its vicious racists, . . . one day right there in Alabama little black boys and black girls will be able to join hands with little white boys and white girls as sisters and brothers. I have a dream today.

# 3.txt
I have a dream that one day every valley shall be exalted, every hill and mountain shall be made low, the rough places will be made plain, and the crooked places will be made straight, and the glory of the Lord shall be revealed, and all flesh shall see it together.

# 4.txt
This is our hope. . . With this faith we will be able to hew out of the mountain of despair a stone of hope. With this faith we will be able to transform the jangling discords of our nation into a beautiful symphony of brotherhood. With this faith we will be able to work together, to pray together, to struggle together, to go to jail together, to stand up for freedom together, knowing that we will be free one day. . . .

# 5.txt
And when this happens, and when we allow freedom ring, when we let it ring from every village and every hamlet, from every state and every city, we will be able to speed up that day when all of God's children, black men and white men, Jews and Gentiles, Protestants and Catholics, will be able to join hands and sing in the words of the old Negro spiritual: "Free at last! Free at last! Thank God Almighty, we are free at last!"

class SearchEngineBase(object):
    def __init__(self):
        pass

    def add_corpus(self, file_path):
        with open(file_path, 'r') as fin:
            text = fin.read()
        self.process_corpus(file_path, text)

    def process_corpus(self, id, text):
        raise Exception('process_corpus not implemented.')

    def search(self, query):
        raise Exception('search not implemented.')

def main(search_engine):
    for file_path in ['1.txt', '2.txt', '3.txt', '4.txt', '5.txt']:
        search_engine.add_corpus(file_path)

    while True:
        query = input()
        results = search_engine.search(query)
        print('found {} result(s):'.format(len(results)))
        for result in results:
            print(result)

class  SimpleEngine(SeachEngineBase):
    def __init__(self):
        super(SimpleEngine,self).__init__()
        self.__id_to_texts={}
       
    def process_cropus(self,id,text):
        self.__id_to_texts[id]=text
        
    def search(self,query):
        results=[]
        for id,text in self.__id_to_texts.item():
            if query in text:
                results.append[id]
        return results
    
search_engin=SimpleEngine
main(SimpleEngine)

class SimpleEngine(SearchEngineBase):
    def __init__(self):
        super(SimpleEngine, self).__init__()
        self.__id_to_texts = {}

    def process_corpus(self, id, text):
        self.__id_to_texts[id] = text

    def search(self, query):
        results = []
        for id, text in self.__id_to_texts.items():
            if query in text:
                results.append(id)
        return results

search_engine = SimpleEngine()
main(search_engine)

########## 输出 ##########


simple
found 0 result(s):
little
found 2 result(s):
1.txt
2.txt

import re
class BOWengine(SearchEngineBase):
    def __init__(self):
        super(BOWengine,self).__init__()
        self.__id_to_words={}
        
    def process_cropus(self,id,text):
        sellf.__id_to_words[id]=self.parse_text_to_words(text)
       
    def search(self,query):
        query_words=self.parse_text_to_words(query)
        results=[]
        for id,text in self.__id_to_words.items():
            if self.query_match(query_words,words):
                results.append(id)
        return results
    
    @staticmethod
    def query_match(query_words,words):
        for query_word in  query_words:
            if query_word not in words:
                return False
        return  True
    
    @staticmethod
    def parse_text_to_words(text):
        text=re.sub(r'[^w]',' ',text)  #使用正则表达式去除标点符号和换行符
        text=text.lower()               #转化为小写
        word_list=text.split(' ')       #生成单词列表
        word_list=filter(None,word_list)#去除空白单词
        return set(world_list)
    
search_engine = BOWEngine()
main(search_engine)


########## 输出 ##########


i have a dream
found 3 result(s):
1.txt
2.txt
3.txt
freedom children
found 1 result(s):
5.txt

import re

class BOWInvertedIndexEngine(SearchEngineBase):
    def __init__(self):
        super(BOWInvertedIndexEngine, self).__init__()
        self.inverted_index = {}

    def process_corpus(self, id, text):
        words = self.parse_text_to_words(text)
        for word in words:
            if word not in self.inverted_index:
                self.inverted_index[word] = []
            self.inverted_index[word].append(id)

    def search(self, query):
        query_words = list(self.parse_text_to_words(query))
        query_words_index = list()
        for query_word in query_words:
            query_words_index.append(0)
        
        # 如果某一个查询单词的倒序索引为空，我们就立刻返回
        for query_word in query_words:
            if query_word not in self.inverted_index:
                return []
        
        result = []
        while True:
            
            # 首先，获得当前状态下所有倒序索引的 index
            current_ids = []
            
            for idx, query_word in enumerate(query_words):
                current_index = query_words_index[idx]
                current_inverted_list = self.inverted_index[query_word]
                
                # 已经遍历到了某一个倒序索引的末尾，结束 search
                if current_index >= len(current_inverted_list):
                    return result

                current_ids.append(current_inverted_list[current_index])

            # 然后，如果 current_ids 的所有元素都一样，那么表明这个单词在这个元素对应的文档中都出现了
            if all(x == current_ids[0] for x in current_ids):
                result.append(current_ids[0])
                query_words_index = [x + 1 for x in query_words_index]
                continue
            
            # 如果不是，我们就把最小的元素加一
            min_val = min(current_ids)
            min_val_pos = current_ids.index(min_val)
            query_words_index[min_val_pos] += 1

    @staticmethod
    def parse_text_to_words(text):
        text=re.sub(r'[^w]',' ',text)  #使用正则表达式去除标点符号和换行符
        text=text.lower()               #转化为小写
        word_list=text.split(' ')       #生成单词列表
        word_list=filter(None,word_list)#去除空白单词
        return set(world_list)
    

search_engine = BOWInvertedIndexEngine()
main(search_engine)


########## 输出 ##########


little
found 2 result(s):
1.txt
2.txt
little vicious
found 1 result(s):
2.txt

import pylru

class LRUCache(object):
    def __init__(self, size=32):
        self.cache = pylru.lrucache(size)
    
    def has(self, key):
        return key in self.cache
    
    def get(self, key):
        return self.cache[key]
    
    def set(self, key, value):
        self.cache[key] = value

class BOWInvertedIndexEngineWithCache(BOWInvertedIndexEngine, LRUCache):
    def __init__(self):
        super(BOWInvertedIndexEngineWithCache, self).__init__()
        LRUCache.__init__(self)
    
    def search(self, query):
        if self.has(query):
            print('cache hit!')
            return self.get(query)
        
        result = super(BOWInvertedIndexEngineWithCache, self).search(query)
        self.set(query, result)
        
        return result

search_engine = BOWInvertedIndexEngineWithCache()
main(search_engine)


########## 输出 ##########


little
found 2 result(s):
1.txt
2.txt
little
cache hit!
found 2 result(s):
1.txt
2.txt

super(子类,self).函数(参数)