Tutorial by Examples: f

Each requirements files should match the name of a settings files. Read Using multiple settings for more information. Structure djangoproject ├── config │ ├── __init__.py │ ├── requirements │ │ ├── base.txt │ │ ├── dev.txt │ │ ├── test.txt │ │ └── prod.txt │ └── setti...

HTML also provides the tables with the <thead>, <tbody>, <tfoot>, and <caption> elements. These additional elements are useful for adding semantic value to your tables and for providing a place for separate CSS styling. When printing out a table that doesn't fit onto one (pa...

var user = Sitecore.Security.Accounts.User.FromName("sitecore/testname", false); using (new Sitecore.Security.Accounts.UserSwitcher(user)) { var item = Sitecore.Context.Database.GetItem("/sitecore/content/home"); }

Just like in case of the function arguments, template parameters can have their default values. All template parameters with a default value have to be declared at the end of the template parameter list. The basic idea is that the template parameters with default value can be omitted while template ...

When you create an argparse ArgumentParser() and run your program with '-h' you get an automated usage message explaining what arguments you can run your software with. By default, positional arguments and conditional arguments are separated into two categories, for example, here is a small script ...

#Post to pagerduty.com notification pagerduty { post = https://events.pagerduty.com/generic/2010-04-15/create_event.json contentType = application/json runOnActions = false body = `{ "service_key": "myservicekey", "incident_key": {{.|jso...

The effect of using the * operator on an argument when calling a function is that of unpacking the list or a tuple argument def print_args(arg1, arg2): print(str(arg1) + str(arg2)) a = [1,2] b = tuple([3,4]) print_args(*a) # 12 print_args(*b) # 34 Note that the length of the starr...

In many other languages, if you run the following (Java example) if("asgdsrf" == 0) { //do stuff } ... you'll get an error. You can't just go comparing strings to integers like that. In Python, this is a perfectly legal statement - it'll just resolve to False. A common gotcha ...

<button tabindex="-1">This button will not be reachable by tab</button> The element will be removed from the tabbing order but will still be focusable.

<div tabindex="2">Second</div> <div tabindex="1">First</div> Positive values will insert the element at the tabbing order position of its respective value. Elements without preference (i.e. tabindex="0" or native elements such as button and a...

// Core Data stack lazy var applicationDocumentsDirectory: NSURL = { let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask) return urls[urls.count-1] }() lazy var managedObjectModel: NSManagedObjectModel = { let modelURL = NSB...

lazy var persistentContainer: NSPersistentContainer = { let container = NSPersistentContainer(name: "ProjectName") container.loadPersistentStores(completionHandler: { (storeDescription, error) in if let error = error { fatalError("Unreso...

go() method The go() method loads a specific URL from the history list. The parameter can either be a number which goes to the URL within the specific position (-1 goes back one page, 1 goes forward one page), or a string. The string must be a partial or full URL, and the function will go to the f...

This method looks for the existence of browser specific things. This would be more difficult to spoof, but is not guaranteed to be future proof. // Opera 8.0+ var isOpera = (!!window.opr && !!opr.addons) || !!window.opera || navigator.userAgent.indexOf(' OPR/') >= 0; // Firefox 1.0+ ...

When you are copying a string into a malloced buffer, always remember to add 1 to strlen. char *dest = malloc(strlen(src)); /* WRONG */ char *dest = malloc(strlen(src) + 1); /* RIGHT */ strcpy(dest, src); This is because strlen does not include the trailing \0 in the length. If you take the ...

A programming best practice is to free any memory that has been allocated directly by your own code, or implicitly by calling an internal or external function, such as a library API like strdup(). Failing to free memory can introduce a memory leak, which could accumulate into a substantial amount of...

If realloc fails, it returns NULL. If you assign the value of the original buffer to realloc's return value, and if it returns NULL, then the original buffer (the old pointer) is lost, resulting in a memory leak. The solution is to copy into a temporary pointer, and if that temporary is not NULL, th...

Before any MPI commands can be run, the environment needs to be initialized, and finalized in the end: int main(int argc, char** argv) { int res; res = MPI_Init(&argc,&argv); if (res != MPI_SUCCESS) { fprintf (stderr, "MPI_Init failed\n"); exit (...

Floating point types (float, double and long double) cannot precisely represent some numbers because they have finite precision and represent the values in a binary format. Just like we have repeating decimals in base 10 for fractions such as 1/3, there are fractions that cannot be represented fini...

Using the calendar module import calendar from datetime import date def monthdelta(date, delta): m, y = (date.month+delta) % 12, date.year + ((date.month)+delta-1) // 12 if not m: m = 12 d = min(date.day, calendar.monthrange(y, m)[1]) return date.replace(day=d,month=m, year=...