打印列表中的數據會出現錯位

Question

我有一個代碼，用於讀取庫存txt文件，該文件假設在用戶運行時顯示一個菜單。然而，在運行時的數量和費用相加列錯位：

Select an item ID to purchase or return: 

ID Item   Quantity Price 
244 Large Cake Pan  7.00 19.99 
576 Assorted Sprinkles  3.00 12.89 
212 Deluxe Icing Set  6.00 37.97 
827 Yellow Cake Mix 3.00 1.99 
194 Cupcake Display Board  2.00 27.99 
285 Bakery Boxes  7.00 8.59 
736 Mixer  5.00 136.94 

Enter another item ID or 0 to stop 

這裏是我的代碼：

import InventoryFile 
def readFile(): 
    #open the file and read the lines 
    inventoryFile = open ('Inventory.txt', 'r') 
    raw_data = inventoryFile.readlines() 

    #remove the new line characters 
    clean_data = [] 
    for item in raw_data: 
     clean_item = item.rstrip ('\n') 
     clean_data.append (clean_item) 

    #read lists into objects 
    all_objects = [] 
    for i in range (0, len(clean_data), 4): 
     ID = clean_data [i] 
     item = clean_data [i+1] 
     qty = float (clean_data [i+2]) 
     price = float (clean_data [i+3]) 

     inventory_object = InventoryFile.Inventory (ID, item, qty, price) 

     all_objects.append (inventory_object) 

    return all_objects 

def printMenu (all_data): 
    print() 
    print ('Select an item ID to purchase or return: ') 
    print() 
    print ('ID\tItem\t\t Quantity\t Price') 

    for item in all_data: 
     print (item) 

    print() 

    print ('Enter another item ID or 0 to stop') 

def main(): 
    all_items = readFile() 
    printMenu (all_items) 

main() 

我如何格式化輸出，這樣的數量和價格列正確對齊？

這裏是庫存類：

class Inventory: 
    def __init__ (self, new_id, new_name, new_stock, new_price): 
     self.__id = new_id 
     self.__name = new_name 
     self.__stock = new_stock 
     self.__price = new_price 

    def get_id (self): 
     return self.__id 
    def get_name (self): 
     return self.__name 
    def get_stock (self): 
     return self.__stock 
    def get_price (self): 
     return self.__price 

    def restock (self, new_stock): 
     if new_stock < 0: 
      print ('ERROR') 
      return False 
     else: 
      self.__stock = self.__stock + new_stock 
      return True 

    def purchase (self, purch_qty): 
     if (new_stock - purch_qty < 0): 
      print ('ERROR') 
      return False 
     else: 
      self.__stock = self.__stock + purch_qty 
      return True 

    def __str__ (self): 
     return self.__id + '\t' + self.__name + '\t' + \ 
     format (self.__stock, '7.2f') + format (self.__price, '7.2f') 

Answer 1

使用類Inventory的干將，你可以做一個列表和剛剛加入的輸出。

def printMenu (all_data): 
    print() 
    print ('Select an item ID to purchase or return: ') 
    print() 
    print ('ID\tItem\t\t Quantity\t Price') 

    for item in all_data: 
     product_id = item.get_id() 
     product_name = item.get_name() 
     product_stock = item.get_stock() 
     product_price = item.get_price() 
     output = [product_id, product_name, product_stock, product_price] 
     output = [str(item) for item in output] 
     print('{:<5}\t{:<5}\t{:<5}\t{:<5}'.format(output)) 

    print() 

    print ('Enter another item ID or 0 to stop')