lambda

问题 I want to know what exactly is lambda in python? and where and why it is used. thanks 回答1: Lambda is more of a concept or programming technique then anything else. Basically it's the idea that you get a function (a first-class object in python) returned as a result of another function instead of an object or primitive type. I know, it's confusing. See this example from the python documentation: def make_incrementor(n): return lambda x: x + n f = make_incrementor(42) f(0) >>> 42 f(1) >>> 43 So

问题 I want to know what exactly is lambda in python? and where and why it is used. thanks 回答1: Lambda is more of a concept or programming technique then anything else. Basically it's the idea that you get a function (a first-class object in python) returned as a result of another function instead of an object or primitive type. I know, it's confusing. See this example from the python documentation: def make_incrementor(n): return lambda x: x + n f = make_incrementor(42) f(0) >>> 42 f(1) >>> 43 So

问题 I want to know what exactly is lambda in python? and where and why it is used. thanks 回答1: Lambda is more of a concept or programming technique then anything else. Basically it's the idea that you get a function (a first-class object in python) returned as a result of another function instead of an object or primitive type. I know, it's confusing. See this example from the python documentation: def make_incrementor(n): return lambda x: x + n f = make_incrementor(42) f(0) >>> 42 f(1) >>> 43 So

问题 I want to know what exactly is lambda in python? and where and why it is used. thanks 回答1: Lambda is more of a concept or programming technique then anything else. Basically it's the idea that you get a function (a first-class object in python) returned as a result of another function instead of an object or primitive type. I know, it's confusing. See this example from the python documentation: def make_incrementor(n): return lambda x: x + n f = make_incrementor(42) f(0) >>> 42 f(1) >>> 43 So

问题 I want to know what exactly is lambda in python? and where and why it is used. thanks 回答1: Lambda is more of a concept or programming technique then anything else. Basically it's the idea that you get a function (a first-class object in python) returned as a result of another function instead of an object or primitive type. I know, it's confusing. See this example from the python documentation: def make_incrementor(n): return lambda x: x + n f = make_incrementor(42) f(0) >>> 42 f(1) >>> 43 So

问题 In Java I have the following code List<Integer> myList = new ArrayList<>(); for (int i=0;i<9;i++) { myList.add(i); } Integer sum = 0; myList.forEach(i -> { sum = sum + i; // does not compile, sum needs to be final or effectively final }); for(int i : myList) { sum = sum + i; //runs without problems } My question is, why is it exactly that I cannot change the value of sum from within the lambda? It does the exact same thing as the for loop down below, or am I wrong? Interesting is also the

问题 In Java I have the following code List<Integer> myList = new ArrayList<>(); for (int i=0;i<9;i++) { myList.add(i); } Integer sum = 0; myList.forEach(i -> { sum = sum + i; // does not compile, sum needs to be final or effectively final }); for(int i : myList) { sum = sum + i; //runs without problems } My question is, why is it exactly that I cannot change the value of sum from within the lambda? It does the exact same thing as the for loop down below, or am I wrong? Interesting is also the

问题 In Java I have the following code List<Integer> myList = new ArrayList<>(); for (int i=0;i<9;i++) { myList.add(i); } Integer sum = 0; myList.forEach(i -> { sum = sum + i; // does not compile, sum needs to be final or effectively final }); for(int i : myList) { sum = sum + i; //runs without problems } My question is, why is it exactly that I cannot change the value of sum from within the lambda? It does the exact same thing as the for loop down below, or am I wrong? Interesting is also the

问题 I am trying to use some of the new features of Mockito, specifically mocking of static methods. I am able to get it to work when the method I am mocking has no parameters, but for some reason it will not work if the method has any parameters. As the example below is written, the test assertEquals( "bar", Foo.foo() ) works but the test assertEquals(2, map.size() ) fails as no behavior has been defined for the mocked class. fooMock.when(Foo::genMap).thenCallRealMethod() gives the follwing

问题 I'm familiar with serverless and MongoDB and would like to know if there are any scalable ways to connect the two worlds. As far as I know, you can't interact with MongoDB in a RESTful way. Instead, opening a connection which is supposed to be reused. Let's say I'm using AWS Lambda as part of a serverless API. When the lambda is cold you have to open a new connection to MongoDB and while the lambda is still hot, the connection remains open. This solution is fine, but when you have a surge of