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How to check whether a file or directory exists?

...iven file or directory exists func exists(path string) (bool, error) { _, err := os.Stat(path) if err == nil { return true, nil } if os.IsNotExist(err) { return false, nil } return false, err } Edited to add error handling. ...
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How do I make a checkbox required on an ASP.NET form?

...ion for client side validation (using jQuery)... function CheckBoxRequired_ClientValidate(sender, e) { e.IsValid = jQuery(".AcceptedAgreement input:checkbox").is(':checked'); } code-behind for server side validation... protected void CheckBoxRequired_ServerValidate(object sender, ServerValid...
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Convert Python dictionary to JSON array

... If you are fine with non-printable symbols in your json, then add ensure_ascii=False to dumps call. >>> json.dumps(your_data, ensure_ascii=False) If ensure_ascii is false, then the return value will be a unicode instance subject to normal Python str to unicode coercion rules in...
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Android Writing Logs to text File

... code of Mine but then this method creates file but contains nothing. Basically I want to read previous contents of the file and then append my data with the existing content. ...
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Annotating text on individual facet in ggplot2

... Typically you'd do something like this: ann_text <- data.frame(mpg = 15,wt = 5,lab = "Text", cyl = factor(8,levels = c("4","6","8"))) p + geom_text(data = ann_text,label = "Text") It should work without specifying the factor variable comple...
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How can I clear event subscriptions in C#?

...ist, effectively. From outside the class, you can't do this - events basically expose "subscribe" and "unsubscribe" and that's it. It's worth being aware of what field-like events are actually doing - they're creating a variable and an event at the same time. Within the class, you end up referenci...
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Static nested class in Java, why?

...ike any other top-level class. In effect, a static nested class is behaviorally a top-level class that has been nested in another top-level class for packaging convenience. There is no need for LinkedList.Entry to be top-level class as it is only used by LinkedList (there are some other interface...
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How do I insert datetime value into a SQLite database?

...ient method, but I tend to forgo strong datatypes in SQLite since they are all essentially dumped in as strings anyway. I've written a thin C# wrapper around the SQLite library before (when using SQLite with C#, of course) to handle insertions and extractions to and from SQLite as if I were dealin...
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Reading header data in Ruby on Rails

..."Cookie"] New way: request.headers["HTTP_COOKIE"] To get a Hash with all headers of the request. request.headers share | improve this answer | follow |...
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Converting from IEnumerable to List [duplicate]

...to a Generic List. //ArrayList Implements IEnumerable interface ArrayList _provinces = new System.Collections.ArrayList(); _provinces.Add("Western"); _provinces.Add("Eastern"); List<string> provinces = _provinces.Cast<string>().ToList(); If you're using Generic version IEnumerable&...