附加文件时删除新线路

Question

我有一个问题，当我附加到文件时，始终出于某种原因始终添加新线。这打破了我的代码。它是某种登录系统。我已经搜索了很多答案。目前，我找到了.rstrip（'\ r'），.strip（'\ t'） and .strip（'\ n'）没有工作。

示例：

时，我将其写入这样的文件

print("Create")
with open('database.txt', 'a') as database:
    username = input("Enter a username: ")
    password = input("Enter a password: ")
    combined = (password + "," + username + "<>")
    combined = combined.strip('\n')
    combined = combined.strip('')
    combined = combined.strip(' ')
    combined = combined.rstrip('\r')
    combined = combined.strip('\t')
    database.write(combined)
    database.close()

    #checking total number of users
    with open('usernum.txt', 'r+') as usernum:
        #the current number + 1 will be the number of the new user
        total_num_of_users = usernum.read()
        total_num_of_users = int(total_num_of_users) + 1
        #incrementing for future numbers
        total_num_of_users = str(total_num_of_users)
        usernum.truncate(0)
        usernum.write(total_num_of_users)
        usernum.close()

    #making a file containing the users place/number
    namefile = str(username) + '.txt'
    with open(namefile, 'w+') as usernum:
        usernum.write(total_num_of_users)
        usernum.close()

当它已经具有内容password1，username1＆lt;＆gt;：请忽略文件称为database.txt lol 。如果我的输入是username2和password2我的预期输出是：

password1，username1＆lt;＆gt; password2，username2＆lt;＆gt;

但是我得到了：

password1，username1＆lt;＆gt;

password2，username2＆lt;＆gt;

谁能帮我这个？提前致谢