如何修复Python中附加模式下的文件覆盖？

Question

我正在用python用tkinter编写一个register（例如，一个school one）程序，并且我试图在每个人单击submit时向register添加一个新的人，但是所发生的一切是它正在覆盖以前的名称，这意味着它被保存的文件只有一个名称。你知道吗

有人对如何解决这个问题有什么建议吗？你知道吗

更清楚的是：register\u info和listedes\u info是注册者的名字和最新保存到文件中的人的名字。你知道吗

这是我代码的一部分：

def create_register():
    register_info = registername.get()
    listees_info = listees.get()
    list_of_registers=os.listdir()
    if register_info in list_of_registers:
        file=open(register_info,"w")
        file.close()
        Label(create, text = "Register Created", fg = "green" ,font = ("calibri", 8)).pack()
    with open(register_info,"a") as file_info:
        file_info.write(register_info+"\n")
        file_info.write(listees_info+"\n")
        file_info.close()

Answer 1

传递给w的open模式（在您的file=open(register_info,"w")行中）告诉python您要打开文件进行写入。根据设计，这将除去文件中的任何其他内容，并将光标放在开头。听起来像是要打开文件并在末尾附加信息，而不覆盖任何内容。你知道吗

为此，您应该使用append的a模式。这将打开文件进行写入，并将光标放在文件末尾。你知道吗

所以，你需要说open(register_info, "a")。你知道吗

我还建议切换到上下文管理器，以确保在发生任何意外行为时关闭文件。您可以这样做：

with open(register_info, "a") as file:
    # Any code that needs to use "file" here

有关文件打开模式的更多信息（摘自我的另一个答案）：

r: Opens the file in read-only mode. Starts reading from the beginning of the file and is the default mode for the open() function.

rb: Opens the file as read-only in binary format. Places the cursor at the start of the file.

r+: Opens a file for reading and writing. Places the cursor at the beginning of the file.

w: Opens in write-only mode. Places the cursor at the beginning of the file. This will overwrite any existing file with the same name. It will create a new file if one with the same name doesn't exist.

wb: Same behavior as w, except the file is opened in binary mode.

w+: Opens a file for writing and reading. Replaces all content and creates the file if it doesn't exist. This mode is used when you need to write to an empty-file and potentially read from it later in your code (before closing).

wb+: Same behavior as w+ except the file is in binary mode.

a: Opens a file for appending new information to it. The cursor is placed at the end of the file. A new file is created if one with the same name doesn't exist.

ab: Same behavior as a except the file is in binary mode.

a+: Opens a file for both appending and reading. The cursor is placed at the beginning of the file.

ab+: Same as a+ except the file is in binary mode.

Answer 2

您应该修复此部分：

    if register_info in list_of_registers:
        file=open(register_info,"w")
        file.close()

在w模式下打开此文件时，实际上是在重置它。你知道吗