csv-創建登錄系統，python無法從.csv文件正確讀取？

Question

我試圖制作一個基本循環的登錄系統，每當我嘗試輸入正確的詳細信息（甚至存儲在.csv文件中）時，無論我輸入什么內容，它都會輸出為錯誤的用戶名/密碼。 這段代碼適用於python 3.6，但是我需要它才能適用於python 3.2.3。

loop1 = False #for this bit of code (logging in)
loop2 = False #for next bit of code
while loop1 == False:
    choice = input("Login/SignUp [TYPE 'L' OR 'S']: ").lower()
    if choice == "l":
        username = input("Username: ")
        password = input("Password: ")
        f = open("usernamepassword.csv","r")
        for line in f:
            details = line.split(",")
            if username == details[0] and password == details[1]:
                print("Welcome")
                break
                #this whole bit of code is meant to read from the csv and check if the login details are correct
        else:
            print("Username/Password [INCORRECT]")

Answer 1

您可能在line.split（'，'）中存在錯誤，請嘗試使用line.strip（）。split（'，'）

TL; DR：在那發布了一個正確的解決方案： https : //github.com/cgte/stackoverflow-issues/tree/master/47207293-csv-dict

如有需要，我將在后面補充我的答案。

此外，您在這里的代碼設計不佳，並且發現自己在循環中間進行調試。

因此，首先：加載數據文件，將內容存儲到字典中。

    f = open("usernamepassword.csv","r")
    for line in f:
        details = line.split(",")
        if username == details[0] and password == details[1]:
            print("Welcome")
            break

應該成為

    user_pass = {}

    f = open("usernamepassword.csv","r")
    for line in f:
        user, password = line.strip().split(",")
        user_pass[user] = password
    f.close()

或更好

    with open("usernamepassword.csv","r") as f:
        for line in f.readlines():
            user, password = line.split().split(",")
            user_pass[user] = password

最終運行python -i yourfile.py並鍵入“ user_pass”，以查看正確存儲進一步代碼后實際存儲的內容。

考慮使用csv模塊： https : //docs.python.org/3/library/csv.html

然后從輸入中獲取用戶名和密碼並檢查：

if login in user_pass and user_pass[login] = password:
# or better `if user_pass.get(login, None) == password:`
    do_stuff()

Answer 2

請允許我重構您的代碼：

def login(username, password):
    with open("usernamepassword.csv", "r") as csv:
        all_details = 
              [[attr.strip() for attr in line.split(",")]
              for line in csv]
        return any(
               username == details[0] 
               and password == details[1] 
               for details in all_details)

def login_action():
     username = input("Username: ")
     password = input("Password: ")
     if not login(username, password):
         raise ValueError("Username/Password [INCORRECT]")
     return True

_USER_ACTIONS = {
    'l': login_action
}

def main():
    while True:
         choice = input("Login/SignUp [TYPE 'L' or 'S']: ").lower()
         action = _USER_ACTIONS[choice]
         try: 
             if action():
                break
         except Exception as err:
             print(err.message)

我認為您的意外行為是由於不剝離除以之后的值,

Answer 3

通過更換來解決：

if username == details[0] and password == details[1]:

帶有：

if username == details[0] and (password+"\n") == details[1]: