Question

我正在从Windows服务器读取各种日志，当前正在抓取文件夹中的最新日志。

然后，我想扫描该日志，只打印包含特定字符串的最后一行。

以下将打印包含字符串的所有行 -

def read_logfile(master_log):
    for line in master_log:
        if line.contains('[76:Health]:'):
            print line

如何让它只打印它找到的最后一个匹配项？

Answer 1

这样做的简单方法就是每次点击时都存储，并在循环外打印：

var kernel = new StandardKernel();
// Set up kernel

var substitute = Substitute.For<ISubstitutedObject>();
kernel.Bind<ISubstitutedObject>().ToContstant(substitute);

您可以使用collections.deque与适当的protected override void OnCreate(Bundle bundle) { base.OnCreate(bundle); Xamarin.Forms.Forms.Init(this, bundle); Window.SetSoftInputMode(SoftInput.AdjustResize); AndroidBug5497WorkaroundForXamarinAndroid.assistActivity(this); ToolbarResource = Resource.Layout.toolbar; TabLayoutResource = Resource.Layout.tabs; LoadApplication(new App()); } public class AndroidBug5497WorkaroundForXamarinAndroid { // For more information, see https://code.google.com/p/android/issues/detail?id=5497 // To use this class, simply invoke assistActivity() on an Activity that already has its content view set. // CREDIT TO Joseph Johnson (http://stackoverflow.com/users/341631/joseph-johnson) for publishing the original Android solution on stackoverflow.com public static void assistActivity(Activity activity) { new AndroidBug5497WorkaroundForXamarinAndroid(activity); } private Android.Views.View mChildOfContent; private int usableHeightPrevious; private FrameLayout.LayoutParams frameLayoutParams; private AndroidBug5497WorkaroundForXamarinAndroid(Activity activity) { FrameLayout content = (FrameLayout)activity.FindViewById(Android.Resource.Id.Content); mChildOfContent = content.GetChildAt(0); ViewTreeObserver vto = mChildOfContent.ViewTreeObserver; vto.GlobalLayout += (object sender, EventArgs e) => { possiblyResizeChildOfContent(); }; frameLayoutParams = (FrameLayout.LayoutParams)mChildOfContent.LayoutParameters; } private void possiblyResizeChildOfContent() { int usableHeightNow = computeUsableHeight(); if (usableHeightNow != usableHeightPrevious) { int usableHeightSansKeyboard = mChildOfContent.RootView.Height; int heightDifference = usableHeightSansKeyboard - usableHeightNow; frameLayoutParams.Height = usableHeightSansKeyboard - heightDifference; mChildOfContent.RequestLayout(); usableHeightPrevious = usableHeightNow; } } private int computeUsableHeight() { Rect r = new Rect(); mChildOfContent.GetWindowVisibleDisplayFrame(r); if (Build.VERSION.SdkInt < BuildVersionCodes.Lollipop) { return (r.Bottom - r.Top); } return r.Bottom; } }一起推广到最后def read_logfile(master_log): lastmatch = None for line in master_log: if '[76:Health]:' in line: lastmatch = line if lastmatch is not None: print lastmatch次匹配，这样您只需n所有匹配，推出最早的一次你超过了限制。以下工作与上面的代码完全相同，但允许第二个参数打印更多行：

maxlen

Answer 2

将其存储在数组中，然后打印数组中的最后一项。可以使用pop将该行作为str返回。

 def read_logfile(master_log):
        last_line_holder = []
        for line in master_log:
            if line.contains('[76:Health]:'):
                last_line_holder.append(line)
        print(last_line_holder[-1])

Answer 3

您可以按相反的顺序迭代文件。

for line in reversed(master_log.readlines()):
    if '[76:Health]:' in line:
        print(line)
        break

如果您的文件很小，阅读它不会有问题。如果它很大，请选择其他解决方案。

python - 打印文件

3 个答案: