有时会将不正确的数据写入磁盘

Question

我正在开发一个Django项目，它启动一个监视系统资源的异步线程，因为有些请求需要根据服务器的当前状态更改行为。设置监控线程的代码：

def monitor():
    try:
        f = open("file")
        data = eval(f.read())  # raises SyntaxError!?
        f.close()
    except FileNotFoundError:
        data = {
            "cpu": [0 for _ in range(720)],
            "ram": [0 for _ in range(720)],
            "disk_capacity": [0 for _ in range(720)],
            "disk_write": [0 for _ in range(720)],
            "disk_read": [0 for _ in range(720)],
            "network_sent": [0 for _ in range(720)],
            "network_recv": [0 for _ in range(720)],
            "uptime": 0
        }

    while True:
        f = open("file", "w")
        f.write(str(data))
        f.close()
        data = update_data(data)  # Returns every full hour

class ServerStatusConfig(AppConfig):
    ...

    def ready(self):
        # Workaround for Django's process forking
        try:
            f = open("temp", "r")
            f.close()
        except FileNotFoundError:
            f = open("temp", "w")
            f.close()
            thread = threading.Thread(target=monitor)
            thread.start()
        else:
            os.remove("temp")

def update_data(data):
    # Fetch cpu, ram, dskcap, dskw, dskr, netr, nets
    # cpu scheduled to calculate average until next full hour,
    # other stats are fetched immediately afterwards
    ...
    data["cpu"] = data["cpu"][1:]+[cpu]
    data["ram"] = data["ram"][1:]+[ram]
    data["disk_capacity"] = data["disk_capacity"][1:]+[dskcap]
    data["disk_write"] = data["disk_write"][1:]+[dskw]
    data["disk_read"] = data["disk_read"][1:]+[dskr]
    data["network_recv"] = data["network_recv"][1:]+[netr]
    data["network_sent"] = data["network_sent"][1:]+[nets]

    return data

基本上，从任何其他代码不读取或写入的文件中读取str(data)会经常引发语法错误。语法文件中的错误始终由文件末尾的附加]}引起。这意味着数据是可恢复的，并且这确实在技术上解决了问题：

except SyntaxError:
    data = eval(f.read()[:-2])

但偶尔将不正确的数据写入文件可能是什么原因？

修改：更新了代码，以便在创建时显示data字典内容。

修改：更新了代码以显示update_data功能。