读取在python

Question

我试图在python中读取每20秒更新一次的日志文件。到目前为止，我只能读取静态文件。我试图读取这些值，使用HighCharts在图表上绘制它们。我可以使用静态文件绘制值。但是我希望图表是实时的。有人可以帮我这个吗？

with open(self.filename) as f:
        cpu = []
        idle = []
        wait = []
        ld5 = []
        ld10 = []
        ld15 = []
        load = []
        swapu = []
        swapf = []

        #need to remove all the white space in the file
        for line in f:
            if line is not None:
                    stripped = line.strip()
                    dstat_tokens = self.whitespace_re.split(stripped)           
            #dstat_tokens = self.whitespace_re.split(stripped)
                    dstat_tokens = line.split(',')
                    (timestamp) = dstat_tokens[0:1]
                    (system,user,idl, wt, hwi, sfi) = dstat_tokens[1:7];
                    (diskread,diskwrite) = dstat_tokens[7:9]
                    (pagein,pageout) = dstat_tokens[9:11]
                    (load5,load10,load15) = dstat_tokens[11:14]
                    (used,buffers,cache,free) = dstat_tokens[14:18]
                    (swapused,swapfree) = dstat_tokens[18:20]
                    (interrupts,contextswitches) = dstat_tokens[20:22]
                    (receive,send) = dstat_tokens[22:24]
                    (runnable,uninterruptable,new) = dstat_tokens[24:27]

                #print "Stripping %s" % timestamp[0]
                    ts = time.strptime(timestamp[0], "%d %b %Y %H:%M:%S CET")
                    dt = datetime.fromtimestamp(time.mktime(ts))
                    returned_time = dt.strftime("%d/%m/%Y %H:%M:%S")
                #print returned_time

                    cpu.append({"ts": returned_time, "value": float(system)})
                    idle.append({"ts": returned_time, "value": float(idl)})
                    wait.append({"ts": returned_time, "value": float(wt)})
                    ld5.append({"ts": returned_time, "value": float(load5)})
                    ld10.append({"ts": returned_time, "value": float(load10)})
                    ld15.append({"ts": returned_time, "value": float(load15)})
                    load.append({"ts": returned_time, "value": float(load5)})
                    swapu.append({"ts": returned_time, "value": float(swapused)})
                    swapf.append({"ts": returned_time, "value": float(swapfree)})

            self.data["cpu"] = cpu
            self.data["idle"] = idle
            self.data["load5"] = ld5
            self.data["load10"] = ld10
            self.data["load15"] = ld15
            self.data["swapused"] = swapu
            self.data["swapfree"] = swapf`

Answer 1

我理解您的问题的方式是，您希望每次更新日志文件时都更新图表。您可以通过每次阅读时将文件的长度存储在txt文档中，然后每隔x秒更新图表，检查txt文档并从中获取文件位置{{1}到那个位置。

seek()

我在我的python上生锈了，并且不记得如何准确地做到这一点，但这是一般的想法。如果有人知道如何实际执行此操作，请更新我的代码。如果您有任何问题，请告诉我，我会尝试澄清。