程序什麼時候什麼都沒有提示

Question

我寫了一個程序很匆忙，看看我是否可以改進一些我放棄的舊代碼，因爲我無法保存它，但現在我已經寫入了一個。 csv文件它什麼都不做。如果我在運行時嘗試與它交互，即按1,2,3,4，則什麼都不會發生，它甚至不會退出，原因是我無法排除故障。這裏是代碼，任何人都可以告訴我我失蹤了什麼？

import pandas as pd 
import csv 
import matplotlib.pyplot as plt 
import numpy as np 

myDict = {"Apples": 150, "Berries": 200, "Bananas": 300, "Oranges": 350} 

def menu(): 
    print("Press 1: To add stock. ") 
    print("Press 2: To check stock. ") 
    print("press 3: To enter purchase. ") 
    print("Press 4: To quit the program. ") 
    return input("What would you like to do? ") 

run = menu() 

while True: 
    if run == '1': 
     AddStock = input('Product to be added to stock? ') 
     Amount = int(input('Quantity of product to be added to stock? ')) 
     myDict[AddStock] = Amount 
     run = menu() 

    elif run == '2': 
     for key, value in myDict.items(): 
      print("{}: {}".format(key, value)) 
     run = menu() 

    elif run == '3': 
     product = input('What product was sold? ') 
     if product in myDict: 
       myDict[product] -= 1 
     else: 
      print("Product is out of stock! ") 
     run = menu() 

    elif run == '4': 
     with open('stock.csv', 'w') as stock: 
      writer = csv.writer(stock) 
      for key, value in myDict.items(): 
       writer.writerow([key, value]) 
       break 

Answer 1

既然沒有人回答了這個問題......下面是一個快速解決問題的方法。雖然，我只會顯示一次命令選項，而不是每次都顯示。

import csv 

myDict = {"Apples": 150, "Berries": 200, "Bananas": 300, "Oranges": 350} 

def menu(): 
    print("Press 1: To add stock.") 
    print("Press 2: To check stock.") 
    print("press 3: To enter purchase.") 
    print("Press 4: To quit the program.") 
    return input("What would you like to do? ") 

run = None 
while run != '4': 
    run = menu() 
    if run == '1': 
     AddStock = input('Product to be added to stock? ') 
     Amount = int(input('Quantity of product to be added to stock? ')) 
     myDict[AddStock] = Amount 
    elif run == '2': 
     for key, value in myDict.items(): 
      print("{}: {}".format(key, value)) 

    elif run == '3': 
     product = input('What product was sold? ') 
     if product in myDict: 
      myDict[product] -= 1 
     else: 
      print("Product is out of stock! ") 

    elif run == '4': 
     with open('stock.csv', 'w', newline="") as stock: 
      writer = csv.writer(stock) 
      for key, value in myDict.items(): 
       writer.writerow([key, value])