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Swift timer.fire() Objective-C [timer fire]; Calling the fire method causes an NSTimer to perform the task it would have usually performed on a schedule. In a non-repeating timer, this will automatically invalidate the timer. That is, calling fire before the time interval is up will result ...

Swift timer.invalidate() Objective-C [timer invalidate]; This will stop the timer from firing. Must be called from the thread the timer was created in, see Apple's notes: You must send this message from the thread on which the timer was installed. If you send this message from another thr...

5.1 JavaScript does not directly support enumerators but the functionality of an enum can be mimicked. // Prevent the enum from being changed const TestEnum = Object.freeze({ One:1, Two:2, Three:3 }); // Define a variable with a value from the enum var x = TestEnum.Two; // Prin...

For example, if t1 is currently not an InnoDB table, this statement changes its storage engine to InnoDB: ALTER TABLE t1 ENGINE = InnoDB; If the table is already InnoDB, this will rebuild the table and its indexes and have an effect similar to OPTIMIZE TABLE. You may gain some disk space improv...

Below won't work on a Windows machine $file = $request->file('file_upload'); $sampleName = 'UserUpload'; $destination = app_path() . '/myStorage/'; $fileName = $sampleName . '-' . date('Y-m-d-H:i:s') . '.' . $file->getClientOriginalExtension(); $file->move($destination, $fileName); ...

Like lists and tuples, you can include a trailing comma in your dictionary. role = {"By day": "A typical programmer", "By night": "Still a typical programmer", } PEP 8 dictates that you should leave a space between the trailing comma and the closi...

There are three kinds of numeric RangeFields in Python. IntegerField, BigIntegerField, and FloatField. They convert to psycopg2 NumericRanges, but accept input as native Python tuples. The lower bound is included and the upper bound is excluded. class Book(models.Model): name = CharField(max_l...

add 'django.contrib.postgres' to your INSTALLED_APPS install psycopg2

It's simpler and easier to input values as a Python tuple instead of a NumericRange. Book.objects.create(name='Pro Git', ratings_range=(5, 5)) Alternative method with NumericRange: Book.objects.create(name='Pro Git', ratings_range=NumericRange(5, 5))

This query selects all books with any rating less than three. bad_books = Books.objects.filter(ratings_range__contains=(1, 3))

This query gets all books with ratings greater than or equal to zero and less than six. all_books = Book.objects.filter(ratings_range_contained_by=(0, 6))

This query gets all overlapping appointments from six to ten. Appointment.objects.filter(time_span__overlap=(6, 10))

This query selects all books with any rating greater than or equal to four. maybe_good_books = Books.objects.filter(ratings_range__contains=(4, None))

the timedelta module comes in handy to compute differences between times: from datetime import datetime, timedelta now = datetime.now() then = datetime(2016, 5, 23) # datetime.datetime(2016, 05, 23, 0, 0, 0) Specifying time is optional when creating a new datetime object delta = now-then ...

To remove extraneous packages (packages that are installed but not in dependency list) run the following command: npm prune To remove all dev packages add --production flag: npm prune --production More on it

To generate a list (tree view) of currently installed packages, use npm list ls, la and ll are aliases of list command. la and ll commands shows extended information like description and repository. Options The response format can be changed by passing options. npm list --json json - Sh...

When using a VCS such as Git or SVN, there are some secret data that must never be versioned (whether the repository is public or private). Among those data, you find the SECRET_KEY setting and the database password. A common practice to hide these settings from version control is to create a file...

The try { ... } catch ( ... ) { ... } control structure is used for handling Exceptions. String age_input = "abc"; try { int age = Integer.parseInt(age_input); if (age >= 18) { System.out.println("You can vote!"); } else { System.out.println(...

Since npm itself is a Node.js module, it can be updated using itself. If OS is Windows must be running command prompt as Admin npm install -g npm@latest If you want to check for updated versions you can do: npm outdated In order to update a specific package: npm update <package name>...

Specific to Windows System and android Phone: Requirements: USB Cable Android Device Android Driver Software Basically after connecting USB cable PC detects the Android Device and it will automatically search for the required Drivers for that Android Device. If that drivers are not found th...