我需要幫助在我的詞典程序

Question

def createdictionary(): 
    mydictionary = dict() 
    mydictionary['Computer']='Computer is an electronic machine.' 
    mydictionary['RAM']='Random Access Memory' 
    return mydictionary 

def insert(dictionary): 
    print("Enter the keyword you want to insert in the dictionary: ") 
    key=input() 
    print("Enter its meaning") 
    meaning=input() 
    dictionary[key]=meaning 
    f = open('dict_bckup.txt','a') 
    f.write(key) 
    f.write('=') 
    f.write(meaning) 
    f.write(';\n') 
    f.close() 
    print("Do you want to insert again? y/n") 
    ans=input() 
    if (ans == 'y' or ans=='Y'): 
     insert(dictionary) 

def display(dictionary): 
    print("The contents of the dictionary are : ") 
    f = open('dict_bckup.txt','r') 
    print(f.read()) 
    f.close() 

def update(dictionary): 
    print("Enter the word whose meaning you want to update") 
    key=input() 
    #i want to edit the meaning of the key in the text file 
    f = open('dict_bckup.txt','w') 
    if key in dictionary: 
     print(dictionary[key]) 
     print("Enter its new meaning: ") 
     new=input() 
     dictionary[key]=new 
    else: 
     print("Word not found! ") 
    print("Do you want to update again? y/n") 
    ans=input() 
    if (ans=='y' or ans=='Y'): 
     update(dictionary) 

def search(dictionary): 
    print("Enter the word you want to search: ") 
    word=input() 
    if word in dictionary: 
     print(dictionary[word]) 

else: 
    print("Word not found! ") 
print("Do you want to search again? y/n") 
ans=input() 
if(ans=='y' or ans=='Y'): 
    search(dictionary) 


def delete(dictionary): 
    print("Enter the word you want to delete: ") 
    word=input() 
    if word in dictionary: 
     del dictionary[word] 
     print(dictionary) 
    else: 
     print("Word not found!") 

    print("Do you want to delete again? y/n ") 
    ans=input() 
    if (ans == 'y' or ans == 'Y'): 
     delete(dictionary) 

def sort(dictionary): 
    for key in sorted(dictionary): 
     print(" %s: %s "%(key,(dictionary[key]))) 


def main(): 
    dictionary=createdictionary() 
    while True: 

     print("""    Menu 
      1)Insert 
      2)Delete 
      3)Display Whole Dictionary 
      4)Search 
      5)Update Meaning 
      6)Sort 
      7)Exit 
      Enter the number to select the coressponding field """) 

     ch=int(input()) 

     if(ch==1): 
      insert(dictionary) 

     if(ch==2): 
      delete(dictionary) 

     if(ch==3): 
      display(dictionary) 

     if(ch==4): 
      search(dictionary) 

     if(ch==5): 
      update(dictionary) 

     if(ch==6): 
      sort(dictionary) 

     if(ch==7):           
      break 


main() 

我是新來的蟒蛇。我一直在努力幾天才能得到這個。但仍然沒有找到解決辦法。事情最初我做了一個簡單的字典程序，它存儲了單詞和它們的含義。然後我想我應該永久保存這些詞。我有些嘗試將文字存儲在文本文件中並顯示它。但我沒有得到如何搜索文本文件中的單詞。假設我找到了這個詞，我想更新它的意思。所以我應該怎麼做。因爲如果我使用'w'來重寫它的整個文本文件，它會被重寫。而且我應該如何刪除它。我知道我在文件中插入單詞的方式也是錯誤的。請幫我解決一下這個。

Answer 1

你說得對，將這些值存儲在一個簡單的文本文件中是一個壞主意。如果你想更新一個單詞，你必須重寫整個文件。而搜索單個單詞時，最終可能會搜索文件中的每個單詞。

有一些專門爲字典設計的數據結構（例如Trie樹），但假設你的字典並不真的很大，你可以使用一個sqlite數據庫。 Python有sqlite3庫。查看documentation瞭解更多信息。

Answer 2

正如@Vaibhav Desai所說，您可以定期編寫整本字典。例如考慮在picklemodule其寫入序列化對象：

import pickle 

class MyDict(object): 
    def __init__(self, f, **kwargs): 
     self.f = f 
     try: 
      # Try to read saved dictionary 
      with open(self.f, 'rb') as p: 
       self.d = pickle.load(p) 
     except: 
      # Failure: recreating 
      self.d = {} 
     self.update(kwargs) 

    def _writeback(self): 
     "Write the entire dictionary to the disk" 
     with open(self.f, 'wb') as p: 
      pickle.dump(p, self.d) 

    def update(self, d): 
     self.d.update(d) 
     self._writeback() 

    def __setitem__(self, key, value): 
     self.d[key] = value 
     self._writeback() 

    def __delitem__(self, key): 
     del self.d[key] 
     self._writeback() 

    ... 

這將改寫整個字典到磁盤每次進行修改，這可能是有意義的某些情況下的時間，但可能不是最有效的。您也可以制定一個更爲巧妙的機制，定期調用_writeback，或要求明確調用_writeback。

正如其他人所建議的，如果你需要大量寫入字典，你會使用sqlite3module，有一個SQL表作爲你的字典會更好：

import sqlite3 

class MyDict(object): 
    def __init__(self, f, **kwargs): 
     self.f = f 
     try: 
      with sqlite3.connect(self.f) as conn: 
       conn.execute("CREATE TABLE dict (key text, value text)") 
     except: 
      # Table already exists 
      pass 

    def __setitem__(self, key, value): 
     with sqlite3.connect(self.f) as conn: 
      conn.execute('INSERT INTO dict VALUES (?, ?)', str(key), str(value)) 

    def __delitem__(self, key): 
     with sqlite3.connect(self.f) as conn: 
      conn.execute('DELETE FROM dict WHERE key=?', str(key)) 

    def __getitem__(self, key): 
     with sqlite3.connect(self.f) as conn: 
      key, value = conn.execute('SELECT key, value FROM dict WHERE key=?', str(key)) 
      return value 

    ... 

這只是一個例如，你可以維持連接打開，並要求它明確關閉，或排隊查詢......但它應該給你一個粗略的想法，你可以如何將數據保存到磁盤。

通常，Python文檔的Data Persistence部分可以幫助您找到最適合您問題的模塊。

Answer 3

首先，每次更新或插入字典時寫入磁盤是一個非常糟糕的主意 - 您的程序只是用盡了太多的I/O。因此，更簡單的方法是將鍵值對存儲在字典中，並在程序退出時或以某個固定的時間間隔將其保存到磁盤中。另外，如果你不喜歡以人類可讀形式（例如純文本文件）將數據存儲在磁盤上，您可以考慮使用如here所示的內置泡菜模塊將數據保存到定義良好的磁盤位置。因此，在程序啓動時，您可以從這個明確定義的位置讀取數據，並將數據「清理」回到字典對象中。這樣您就可以單獨使用字典對象，甚至可以輕鬆完成查找項目或刪除項目等操作。請參閱下面的腳本來解決您的需求。我已經使用pickle模塊來保存該文件，您可能希望將其轉儲到文本文件並作爲單獨的練習讀取它。另外，我還沒有介紹我的功能，例如後綴爲，例如，insert2，以便您可以將您的功能與我的功能進行比較並瞭解其差異：

另一件事 - 您的程序中存在錯誤;你應該使用的raw_input（）如果字典不是太大讀取用戶輸入和不輸入（）

import pickle 
import os 

def createdictionary(): 
    mydictionary = dict() 
    mydictionary['Computer']='Computer is an electronic machine.' 
    mydictionary['RAM']='Random Access Memory' 
    return mydictionary 

#create a dictionary from a dump file if one exists. Else create a new one in memory.  
def createdictionary2(): 

    if os.path.exists('dict.p'): 
     mydictionary = pickle.load(open('dict.p', 'rb')) 
     return mydictionary 

    mydictionary = dict() 
    mydictionary['Computer']='Computer is an electronic machine.' 
    mydictionary['RAM']='Random Access Memory' 
    return mydictionary 

def insert(dictionary): 
    print("Enter the keyword you want to insert in the dictionary: ") 
    key=raw_input() 
    print("Enter its meaning") 
    meaning=raw_input() 
    dictionary[key]=meaning 
    f = open('dict_bckup.txt','a') 
    f.write(key) 
    f.write('=') 
    f.write(meaning) 
    f.write(';\n') 
    f.close() 
    print("Do you want to insert again? y/n") 
    ans=raw_input() 
    if (ans == 'y' or ans=='Y'): 
     insert(dictionary) 

#custom method that simply updates the in-memory dictionary 
def insert2(dictionary): 
    print("Enter the keyword you want to insert in the dictionary: ") 
    key=raw_input() 
    print("Enter its meaning") 
    meaning=raw_input() 
    dictionary[key]=meaning 

    print("Do you want to insert again? y/n") 
    ans=raw_input() 
    if (ans == 'y' or ans=='Y'): 
     insert(dictionary) 



def display(dictionary): 
    print("The contents of the dictionary are : ") 
    f = open('dict_bckup.txt','r') 
    print(f.read()) 
    f.close() 

#custom display function - display the in-mmeory dictionary 
def display2(dictionary): 
    print("The contents of the dictionary are : ") 
    for key in dictionary.keys(): 
     print key + '=' + dictionary[key] 

def update(dictionary): 
    print("Enter the word whose meaning you want to update") 
    key=input() 
    #i want to edit the meaning of the key in the text file 
    f = open('dict_bckup.txt','w') 
    if key in dictionary: 
     print(dictionary[key]) 
     print("Enter its new meaning: ") 
     new=raw_input() 
     dictionary[key]=new 
    else: 
     print("Word not found! ") 
    print("Do you want to update again? y/n") 
    ans=input() 
    if (ans=='y' or ans=='Y'): 
     update(dictionary) 

#custom method that performs update of an in-memory dictionary   
def update2(dictionary): 
    print("Enter the word whose meaning you want to update") 
    key=input() 
    #i want to edit the meaning of the key in the text file 

    if key in dictionary: 
     print(dictionary[key]) 
     print("Enter its new meaning: ") 
     new=raw_input() 
     dictionary[key]=new 
    else: 
     print("Word not found! ") 
    print("Do you want to update again? y/n") 
    ans=raw_input() 
    if (ans=='y' or ans=='Y'): 
     update(dictionary) 

def search(dictionary): 
    print("Enter the word you want to search: ") 
    word=raw_input() 
    if word in dictionary: 
     print(dictionary[word]) 

    else: 
     print("Word not found! ") 
    print("Do you want to search again? y/n") 
    ans=raw_input() 
    if(ans=='y' or ans=='Y'): 
     search(dictionary) 


def delete(dictionary): 
    print("Enter the word you want to delete: ") 
    word=raw_input() 
    if word in dictionary: 
     del dictionary[word] 
     print(dictionary) 
    else: 
     print("Word not found!") 

    print("Do you want to delete again? y/n ") 
    ans=raw_input() 
    if (ans == 'y' or ans == 'Y'): 
     delete(dictionary) 

def sort(dictionary): 
    for key in sorted(dictionary): 
     print(" %s: %s "%(key,(dictionary[key]))) 

#this method will save the contents of the in-memory dictionary to a pickle file 
#of course in case the data has to be saved to a simple text file, then we can do so too 
def save(dictionary): 
    #open the dictionary in 'w' mode, truncate if it already exists 
    f = open('dict.p', 'wb') 
    pickle.dump(dictionary, f) 




def main(): 
    dictionary=createdictionary2() #call createdictionary2 instead of creatediction 
    while True: 

     print("""    Menu 
      1)Insert 
      2)Delete 
      3)Display Whole Dictionary 
      4)Search 
      5)Update Meaning 
      6)Sort 
      7)Exit 
      Enter the number to select the coressponding field """) 

     ch=int(input()) 

     if(ch==1): 
      insert2(dictionary) #call insert2 instead of insert 

     if(ch==2): 
      delete(dictionary) 

     if(ch==3): 
      display2(dictionary) #call display2 instead of display 

     if(ch==4): 
      search(dictionary) 

     if(ch==5): 
      update2(dictionary) #call update2 instead of update 

     if(ch==6): 
      sort(dictionary) 

     if(ch==7):           
      #save the dictionary before exit 
      save(dictionary); 
      break 


main()