我正在创建一个用户系统。我需要将用户名和密码存储在文件中。
情况1：如果现有用户= 我需要阅读用户名和密码来检查现有用户。 我需要检查密码是否与键入值和字典值匹配。
情况2：如果新用户= 我需要检查用户名是否已存在于数据库中。 如果不是这样，我需要在不覆盖现有文件的情况下添加用户名和密码。
这里的问题，我在这里使用了json，但似乎覆盖了现有的字典。
我尝试写入一个简单的文本文件，在读取文件时以及在情况2中检查用户名是否存在时遇到问题。
# Login System Management
import json
class LoginSystem:
def __init__(self): # Opening and reading the registered users json.file
self.users = json.load(open("Users.json"))
self.login_screen()
def login_screen(self): # Log on screen to verify new or old user.
while True:
main_log = input("Are you new user?\n[Y]es or [N]o: ")
if main_log == "Y":
self.new_user()
break
elif main_log == "N":
self.old_user()
break
else:
print("Invalid answer.\n")
def old_user(self): # Log in screen if old user.
while True:
user_id = input("Please enter your user id: ")
user_password = input("Please enter your password: ")
if len(user_id) <= 64 and len(user_password) <= 64 and self.check_system(user_id, user_password):
print("Logging In")
break
else:
print("Wrong password or username!\n")
def check_system(self, name, password): # Checking system to verify old user id and password.
data = self.users
try:
expected_password = data[name]
except KeyError:
return False
if password != expected_password:
return False
return True
def new_user(self): # Log in screen if new user.
while True:
print("\nMax Length is 64 chars.")
reg_id = input("Register your username: ")
reg_password = input("Key in password: ")
if len(reg_id) <= 64 and len(reg_password) <= 64:
if reg_id not in self.users:
print("Loading.....")
self.update_database(reg_id, reg_password)
print("Registered Successfully.")
break
else:
print("User already registered!\n")
self.old_user()
break
else:
print("Error. Max Length is 64 chars.\n")
def update_database(self, new_user_name, new_user_password): # Writing new username and password to json.file
new_username = new_user_name
new_password = new_user_password
field = [new_username, new_password]
with open("Users.json", "w") as f:
json.dump(field, f)
check = LoginSystem()
答案 0 :(得分：0)
我已经找到答案了。如果有人想推荐您可以关注。
首先，我创建了一行username,password行的csv文件，并将其保存在同一目录中。
其余代码如下。
# Login System Management import csv import time
class LoginSystem:
def __init__(self): # Opening
self.login_screen()
def login_screen(self): # Log on screen to verify new or old user.
while True:
main_log = input("Are you new user?\n[Y]es or [N]o: ")
if main_log == "Y":
self.new_user()
break
elif main_log == "N":
self.old_user()
break
else:
print("Invalid answer.\n")
def old_user(self): # Log in screen if old user.
while True:
user_id = input("\nPlease enter your user id: ")
user_password = input("Please enter your password: ")
if len(user_id) <= 64 and len(user_password) <= 64 and self.read_database(user_id, user_password):
print("Successful")
break
else:
print("Wrong password or username!\n")
def new_user(self): # Log in screen if new user.
print("\nMax Length is 64 chars.")
reg_id = input("Register your username: ")
if self.check_database(reg_id) is True:
while True:
reg_password = input("Key in password: ")
if len(reg_id) <= 64 and len(reg_password) <= 64:
print("Loading.....")
time.sleep(2)
self.update_database(reg_id, reg_password)
print("Registered Successfully.")
break
else:
print("Error. Max Length is 64 chars.\n")
else:
print("User Already Exists.\n")
self.old_user()
def read_database(self, name, password): # Checking if password match to username
with open("Users.csv", "r") as f:
reader = csv.reader(f)
user_list = {}
for row in reader:
user_list[row[0]] = row[1]
try:
expected_password = user_list[name]
if password == expected_password:
print("Logging In")
time.sleep(2)
return True
except KeyError:
return False
if password != expected_password:
return False
def check_database(self, new_name): # Checking if new id exists in user database
with open("Users.csv", "r") as f:
reader = csv.reader(f)
user_list = {}
for row in reader:
user_list[row[0]] = row[1]
if new_name in user_list.keys():
return False
elif new_name not in user_list.keys():
return True
def update_database(self, new_user_name, new_user_password): # Writing new username and password to file
with open("Users.csv", "a", newline="\n") as f: # appends the new username and password to new row of line
writer = csv.writer(f)
writer.writerow([new_user_name, new_user_password])
check = LoginSystem()
答案 1 :(得分：0)
问题是您正在以“写入”模式打开csv文件。此模式用新行替换到目前为止您在数据库中编写的内容。请改用“附加”。
with open("Users.json", "a") as f: