assert

我们平时在看代码的时候，或多或少会看到过assert的存在，并且在有些code review也可以通过增加assert来使代码更加健壮。但是即便如此，assert还是很容易被人忽略，可是这个很不起眼的用法，如果用的得当的话，会对我们的代码大有裨益。所以，我们今天就来看一看assert的用法。 什么是assert？ Python的assert可以被看做是一个debug的工具，主要测试一个条件是否满足，如果测试的条件满足，则什么也不执行，相当执行了pass语句；而如果条件不符合，则会抛出AssertionError，并返回具体的错误信息(optional)。他的具体语法是这样的 assert_stmt ::='assert' expression [',',Exception] 我们看看一个简单形式的assert expression的例子： assert 1 == 2 就相当于下面的两行代码： if __debug__: if not expression : raise AssertionError 再开看看另外一种格式 assert 1 == 2,'assertion is wrong' 就相当于下面的两行代码格式 if __debut__: if not expression1:raise AssertionError(expression2) 这里的__debug_

I currently have an XSD file which controls the validation etc towards my corresponding XML file, and I would like to control (preferably using an assert command rather than XLST [as I have no prior knowledge of this]) and be able to ensure there are the same number of abc:Country tags to abc:AccountNumber tags, as one should correspond to the other <abc:Account> <abc:Individual> <abc:Country>Germany</abc:Country> <abc:Country>Australia</abc:Country> <abs:AccountNumber issuedBy="DE">123456</abs:AccountNumber> <abs:AccountNumber issuedBy="AU">654321</abs:AccountNumber> </abc:Individual> </abc

Consider the following service interfaces: public interface IServiceA { void DoSomething(string s); void DoSomething(string s, bool b); } public interface IServiceB { void DoSomething(); } The implementation of IServiceB depends on IServiceA like this: public class ServiceB : IServiceB { private IServiceA _serviceA; public ServiceB(IServiceA serviceA) { _serviceA = serviceA; } public void DoSomething() { _serviceA.DoSomething("Hello", true); } } Ie. the dependency is injected in the constructor. Now consider a unit test for the DoSomething() method. I wish to assert that one of the overloaded

I have some part in my code that uses string view extensively. It would be inconceivable to use std::string everywhere, and char const* won't work since there is associative containers, many comparisons and such operations that are hard to do with plain raw strings. However, there is a place that will eventually deal with a C API, and it needs null terminated strings: auto sv = std::string_view{/* ... */}; c_api(sv.data()); Although this works fine in my case, I'd like to be sure everything is okay and assert that the strings are null terminated, as my system constructing the string views and

This question already has answers here : Closed 7 years ago . Possible Duplicate: What does assert do? assert tests the programmer's assumption during development without writing exception handlers for an exception This is what i got, when i was searching about the assert . Apart from this, people also said, it is alternative of exception handling. Assertion will come into the picture when you don't want to take the time to write the exception handling code. But, i didn't get the working and uses. Anyone explain this example. class AssertExample { public static void main(String[] args) { int x

Can you please help me better understand, what is an appropriate use of “assert” vs “throwing an exception? When is each scenario appropriate? Scenario 1 CODE public Context(Algorythm algo) { if (algo == null) { throw new IllegalArgumentException("Failed to initialize Context"); } this.algo = algo; } TEST public void testContext_null() { try { context = new Context(null); fail(); } catch (IllegalArgumentException e) { assertNotNull(e); } } Scenario 2 CODE public Context(Algorythm algo) { assert (algo != null); this.algo = algo; } TEST public void testContext_null() { try { context = new

2019.09.03 一、基础部分及语法 一、FPGA程序的固化 [USF-XSim-62] 'simulate' step failed with errors. Please check the Tcl console or log files for more information. 1、 在C语言代码中，行结尾反斜杠\ 起到换行作用，用于宏定义和字符串换行。其中宏定义使用居多。如果一行中有很多元素导致太长影响阅读，可以在结尾加 \ 的方式实现换行，编译时会忽略\以及其后的换行符，当做一行处理。………\就是表示一行不间断。 2、 关于各种电压： VCCINT：内部PL核心电压 VCCAUX：辅助PL电压 VCCBRAM：PL BRAM电压 VCCPINT:PS内部核心电压 VCCPAUX：PS辅助电压 VCCDDR:DDR RAM的工作电压 VREFP：XADC正参考电压 VREFN：XADC负参考电压 3、 #ifdef __cplusplus Extern “C”{ #endif 代码说明： 为了在C++代码中调用用c写成的库文件，就需要用extern”C”来告诉编译器：这是一个用C写成的库文件，请用C的方式来链接它们。 二、断言函数 #define Xil_AssertNonvoid(Expression) \ { \ if (Expression) { \ Xil