清除文件后，我无法保存更多数据

Question

我有一段代码，其作用是将数据保存到文本文件中。我还定义了一个函数来清除文件。不幸的是，清除文件后，不再保存任何数据。我正在保存 iperf 的输出。

 def start_client_and_print_results(self):
    '''Start iperf client and print results to console'''

    my_iperf_process = subprocess.Popen([self.initalize_iperf, "-c", self.ip_addr, self.force_flush],stdout=subprocess.PIPE)

    for line in my_iperf_process.stdout:
        print(line)
        self.starting_index_position += 1
        if (self.starting_index_position > self.start_line_to_write_into_file and self.starting_index_position < self.end_line): 
            self.save_results_to_file_txt(str(line) + "\n")
            self.save_results_to_file_csv(str(line) + "\n")

用于保存数据的函数：

def save_results_to_file_txt(self, output):
    '''Save results to a text file'''
    client_results = open("client_results.txt", "a")
    client_results.write(output)
    client_results.close()

清除数据：

def clear_file(self):
    clear = open("client_results.txt", "w")
    clear.close()

上述功能与 tkinter 库一起使用，我为其定义了具有适当功能的按钮。

button_iperf = tk.Button(root, text = "Start iperf client", command = iperfing.start_client_and_print_results)

button_clear = tk.Button(root, text = "Clear", command = iperfing.clear_file)

有什么想法吗？

我尝试在文件定义中使用 with 语句，但没有成功。

函数在类中定义。

class Iperf():
    '''Class to handle iperf client functionality'''
    def __init__(self, initalize_iperf: str, force_flush: str, ip_addr: str, starting_index_position: int, start_line_to_write_into_file: int, end_line: int):
        '''Initialize the iperf client instance'''

        self.initalize_iperf  = initalize_iperf
        self.force_flush = force_flush
        self.ip_addr = ip_addr
        self.starting_index_position = starting_index_position
        self.start_line_to_write_into_file = start_line_to_write_into_file
        self.end_line = end_line

完整的代码如下所示：

class Iperf():
    '''Class to handle iperf client functionality'''
    def __init__(self, initalize_iperf: str, force_flush: str, ip_addr: str, starting_index_position: int, start_line_to_write_into_file: int, end_line: int):
        '''Initialize the iperf client instance'''

        self.initalize_iperf  = initalize_iperf
        self.force_flush = force_flush
        self.ip_addr = ip_addr
        self.starting_index_position = starting_index_position
        self.start_line_to_write_into_file = start_line_to_write_into_file
        self.end_line = end_line

    def start_client_and_print_results(self):
        '''Start iperf client and print results to console'''

        my_iperf_process = subprocess.Popen([self.initalize_iperf, "-c", self.ip_addr, self.force_flush],stdout=subprocess.PIPE)

        for line in my_iperf_process.stdout:
            print(line)
            self.starting_index_position += 1
            if (self.starting_index_position > self.start_line_to_write_into_file and self.starting_index_position < self.end_line): 
                self.save_results_to_file_txt(str(line) + "\n")
                self.save_results_to_file_csv(str(line) + "\n")

        my_iperf_process.kill()

    def start_server(self):
        '''Start iperf server'''
        my_iperf_process = subprocess.Popen(["iperf3","-s","-B", self.ip_addr, self.force_flush],stdout=subprocess.PIPE)

    def save_results_to_file_txt(self, output):
        '''Save results to a text file'''
        client_results = open("client_results.txt", "a")
        client_results.write(output)
        client_results.close()

    def clear_file(self):
        clear = open("client_results.txt", "w")
        clear.close()

我在课堂上使用这些参数。

iperf_path = "iperf3"
force_flush = "--forceflush"
ip_addr = ""  # Example IP address
starting_index_position = 0
start_line = 3
end_line = 14

Answer 1

好吧，我设法找到了一个如下所示的解决方法。我不通过 Python 处理文件保存，而是直接从终端进行：

class Iperf:
    '''Class to handle iperf client functionality'''
    def __init__(self, initialize_iperf: str, force_flush: str, ip_addr: str, starting_index_position: int, start_line_to_write_into_file: int, end_line: int):
        '''Initialize the iperf client instance'''
        self.initialize_iperf = initialize_iperf
        self.force_flush = force_flush
        self.ip_addr = ip_addr
        self.starting_index_position = starting_index_position
        self.start_line_to_write_into_file = start_line_to_write_into_file
        self.end_line = end_line
        self.my_iperf_process = None  # Hold reference to the subprocess

    def start_client_and_print_results(self):
        '''Start iperf client and print results to console'''
        subprocess.run("iperf3 -c ip-address --forceflush > client_results.txt", shell=True)
        

    def start_server(self):
        '''Start iperf server'''
        my_iperf_process = subprocess.Popen(["iperf3", "-s", "-B", self.ip_addr, self.force_flush], stdout=subprocess.PIPE)

    def clear_file(self):
        '''Delete file'''
        os.remove("client_results.txt")

# Example usage:
iperf_instance = Iperf("iperf3", "--forceflush", "ip-address", 0, 5, 20)
iperf_instance.start_client_and_print_results()
iperf_instance.clear_file()
iperf_instance.start_client_and_print_results()

所以即使删除文件后，我也可以再次覆盖它。感谢大家抽出时间！也许我们也会找到另一种解决方案