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Define a lambda expression that raises an Exception

...ef raise_(ex): raise ex y = lambda: raise_(Exception('foobar')) But if your goal is to avoid a def, this obviously doesn't cut it. It does, however allow you to conditionally raise exceptions, e.g.: y = lambda x: 2*x if x < 10 else raise_(Exception('foobar')) Alternatively you can rai...
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How is Racket different from Scheme?

...This answer should be updated. Racket's feature set far outweighs Scheme's now, with modules and language definitions, etc. – CinchBlue Dec 11 '17 at 2:57 1 ...
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How to create abstract properties in python abstract classes

... Since Python 3.3 a bug was fixed meaning the property() decorator is now correctly identified as abstract when applied to an abstract method. Note: Order matters, you have to use @property before @abstractmethod Python 3.3+: (python docs): class C(ABC): @property @abstractmethod ...
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How to create an object for a Django model with a many to many field?

...s class Sample(models.Model): users = models.ManyToManyField(Users) Now, in a shell or other code, create 2 users, create a sample object, and bulk add the users to that sample object. Users().save() Users().save() # Access the through model directly ThroughModel = Sample.users.through use...
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python NameError: global name '__file__' is not defined

... shell when you C-c C-p? python-shell. Is there a way to use this shell as if it were a terminal running the file? There are 3 options for running the shell : CMD DEDICATED SHOW Would one of them do this? – sinekonata Jul 2 at 0:43 ...
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ng-model for `` (with directive DEMO)

...t" ng-model="uploadme.src"/> There are no changes to the directive. Now, it all works like expected. I can grab the value of uploadme.src from my controller using $scope.uploadme. share | imp...
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How do I get the opposite (negation) of a Boolean in Python?

...> value = False >>> not value True So instead of your code: if bool == True: return False else: return True You could use: return not bool The logical negation as function There are also two functions in the operator module operator.not_ and it's alias operator.__not__ i...
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Python multiprocessing pool.map for multiple arguments

...ort product def merge_names(a, b): return '{} & {}'.format(a, b) if __name__ == '__main__': names = ['Brown', 'Wilson', 'Bartlett', 'Rivera', 'Molloy', 'Opie'] with multiprocessing.Pool(processes=3) as pool: results = pool.starmap(merge_names, product(names, repeat=2)) ...
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How do I remove code duplication between similar const and non-const member functions?

... @VioletGiraffe we know that the object wasn't originally created const, as it is a non-const member of a non const object, which we know because we are in a non-const method of said object. The compiler doesn't make this inference, it follows a...
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How do I get a PHP class constructor to call its parent's parent's constructor?

... __construct($bypass = false) { // only perform actions inside if not bypassing if (!$bypass) { } // call Grandpa's constructor parent::__construct(); } } class Kiddo extends Papa { public function __construct() { $bypassPapa = true; ...