python - 在 Python 中使用 csv reader 搜索两个值的最佳方法

Question

我有以下文件 (bankdetails.txt)

customer1,1
customer2,2
customer3,3
customer4,4
customer5,5

以及以下代码旨在:1.要求用户输入customerid和帐号(例如customer1和1)，如果与文件详细信息匹配，则打印“access granted”，否则打印“denied”。

代码如下。(注意我不知道如何继续的地方？)

def read_from_file_csv_method2():
   accessgranted=False
   while accessgranted==False:
      with open("bankdetails.txt","r") as f:
         reader=csv.reader(f)
         for row in reader:
            for field in row:
               username=input("uesrname:")
               accountno=input("account no:")
               if username==field and accountno==?:
                  accessgranted=True
                  break
               else:
                  accessgranted=False

         if accessgranted==True:
            print("Access Granted")
         else:
            print("Sorry, wrong credentials")       

请回答以下问题

1. 使用我的原始代码更正错误。解释可以做什么来访问字段(通过索引)
2. 提出使用 csv 读取器方法实现相同目标的任何更简单的方法

更新:我知道字典是最合适的，但我想针对这个特定场景使用这些构造来解决这个问题。

例如，下面的代码有效，但仅适用于第一次迭代(customer1 和 1)...不适用于其他任何内容。

 if username==row[0] and accountno==row[1]:

下面的代码中使用了上面的内容...但仍然不太有效

def read_from_file_csv_method2():
   accessgranted=False
   while accessgranted==False:
      with open("bankdetails.txt","r") as f:
         reader=csv.reader(f)
         for row in reader:
               username=input("uesrname:")
               accountno=input("account no:")
               if username==row[0] and accountno==row[1]:
                  accessgranted=True
                  break
               else:
                  accessgranted=False

         if accessgranted==True:
            print("Access Granted")
         else:
            print("Sorry, wrong credentials")         

Answer 1

你可以试试这个:

import csv

data = csv.reader(open('filename.txt'))
username=input("uesrname:")
accountno=input("account no:")
new_data = [{a:b for a, b in zip(["name", "id"], i)} for i in data]
if any(i["name"] == username and i["id"] == accountno for i in new_data):
    print("Access Granted")
else:
    print("Sorry, wrong credentials")  

更简单的方法涉及 and 函数和 for 循环:

def check_credentials(users, username, id):
   for user, the_id in users: #here, unpacking from list. user is the first value in the list that is created via iteration.
       if user == username and the_id == id:
             return True #return will break out of the for loop
   return False #if the loop has not been broken out of at the end of the iteration, it will return False

data = csv.reader(open('filename.txt'))
username=input("uesrname:")
accountno=input("account no:")
if check_credentials(data, username, accountno):
    print("Access Granted")
else:
    print("Sorry, wrong credentials")

没有函数:

flag = False
for user, the_id = data: #data is the csv file. 
    if user == username and the_id == accountno:
         flag = True
         break
if flag:
     print("Access Granted")
else:
     print("Sorry, wrong credentials")