程序加載文件，但沒有任何值更改

這是一個基本的程序，應該從預製文件或採取用戶輸入字符串，然後加密並使用凱撒密碼將其保存到文件。程序加載文件，但沒有任何值更改

我的問題是，由於某種原因，當我運行該程序並選擇「加載文件」選項時，它將經過所有代碼而沒有任何錯誤消息，但是.txt文件上的寫入不會被加密，有誰知道如何解決這個問題？

對於代碼的簡潔佈局這裏有一個引擎收錄鏈接： http://pastebin.com/dJJ1M4g7

def main(): 

    #if they want to save the file after the encrypting if statement 
    ans = input("Would you like to save to a file of read a file, press w or  r").lower() 

    if ans == "w": 
     text = input("What is your text you want to enter").lower() 

     save_file(caeser(text)) 

    elif ans == "r": 

     caeser(load_file()) 

# organise loop & function 
def caeser(text): 
     shift = int(input("How much would you like to shift?: ")) 
     shifted_list = [] 
     for letter in text: 
      character_lower = letter.lower() 
      ASCII = ord(character_lower) 
      shift = shift % 26 
      shifted_letter = ASCII + shift 
      shifted_char = chr(shifted_letter) 
      shift_loop = shifted_letter - 26 
      shift_loop_char = chr(shift_loop) 
      if shifted_letter >= 97 and shifted_letter <= 122: 
       shifted_list.append(shifted_char) 
       text = ''.join(shifted_list) 
      elif shift_loop >= 97 and shift_loop <= 122: 
       shifted_list.append(shift_loop_char) 
       text = ''.join(shifted_list) 
      else: 
       shifted_list.append(character_lower) 
       text = ''.join(shifted_list) 

      encrypted = text 

     return encrypted 

def save_file(text): 
    name = input("Enter filename") 
    file = open(name, "w") 
    file.write(text) 
    file.close() 

# error protection needs to be added 
def load_file(): 
    name = input("what is your file name? (include .txt)") 
    file = open(name, "r") 
    text = file.read() 
    file.close() 
    return text 

main()

來源

2015-04-06 George Rees