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How to use if - else structure in a batch file?

...stion about if - else structure in a batch file. Each command runs individually, but I couldn't use "if - else" blocks safely so these parts of my programme doesn't work. How can I do make these parts run? Thank you. ...
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JSON datetime between Python and JavaScript

... The lambda can be adapted to call the base implementation on non-datetime types, so TypeError can be raised if needed: dthandler = lambda obj: obj.isoformat() if isinstance(obj, datetime) else json.JSONEncoder().default(obj) – Pascal...
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How do I create a copy of an object in PHP?

...ass by reference is a bad idea, because it makes the effect of a function call depend on the implementation of the function, rather than on the specification. It's got nothing to do with pass by value being the default. – Oswald Oct 4 '13 at 7:06 ...
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Converting Long to Date in Java returns 1970

...ime.Instant // Represent a moment as seen in UTC. Internally, a count of nanoseconds since 1970-01-01T00:00Z. .ofEpochSecond( 1_220_227_200L ) // Pass a count of whole seconds since the same epoch reference of 1970-01-01T00:00Z. Know Your Data People use various precisions in...
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What is a proper naming convention for MySQL FKs?

...constraints. If a name is not given, InnoDB creates a unique name automatically. In any case, this is the convention that I use: fk_[referencing table name]_[referenced table name]_[referencing field name] Example: CREATE TABLE users( user_id int, name varchar(100) ); CREATE T...
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How are GCC and g++ bootstrapped?

...ilt (optional) repeat step 2 for verification purposes. This process is called bootstrapping. It tests the compiler's capability of compiling itself and makes sure that the resulting compiler is built with all the optimizations that it itself implements. EDIT: Drew Dormann, in the comments, point...
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What is the difference between shallow copy, deepcopy and normal assignment operation?

...ble towards the existing object. The docs explain the difference between shallow and deep copies: The difference between shallow and deep copying is only relevant for compound objects (objects that contain other objects, like lists or class instances): A shallow copy constructs a new...
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How do I import the Django DoesNotExist exception?

...y of the model itself, in this case Answer. Your problem is that you are calling the get method - which raises the exception - before it is passed to assertRaises. You need to separate the arguments from the callable, as described in the unittest documentation: self.assertRaises(Answer.DoesNotExis...
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What's the difference between deque and list STL containers?

What is the difference between the two? I mean the methods are all the same. So, for a user, they work identically. 8 Answ...
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No mapping found for field in order to sort on in ElasticSearch

... I still have the problem but I want the documents to be in the results in all cases even if they don't have the attribute. – c4k Oct 27 '13 at 15:47 ...