python assert

This article mainly introduces the usage of assert in python. The example analyzes the functions and related usage skills of assert, which is of great practical value, you can refer to the following example to describe how to use assert in python. Share it with you for your

The assert statement is also available in C or C ++. Short assertions. The following is a description from Python help document: Assert statements are a convenient way to insert debugging assertions into a program: An assert statement is used to insert a debugging breakpointProgramIs a convenient way. Format o

, +, + , + ] >>> [(x, y) for x in range (1,3) for y in range (4,6)] [(1, 4), (1, 5), (2, 4), (2, 5)] Assert assertThe following statement is true, otherwise assertionerror appearsUsed to check a condition, and if it is true, do nothing. If it is false, it throws a Asserterror and contains an error message.For example: py>x=23py>assertx>0,"xisnotzeroornegative"py>assertx%2==0,"xisnotanevennumber"Traceback(most

There were no trinocular operators before Python 2.5x, but with the development of language, three mesh operators were added after 2.51 " "2 here the main three-mesh operator3 It is also possible to quickly declare variables and assign values to variables by x,y=4,5 this way. 4 " "5x,y=4,56 ifxy:7Small=x8 Else:9Small=yTen Print(small) One A - Print("after the-----is changed to the three mesh operator----") -Small=xifXElsey the Print(small)Someti

The example in this article describes the assert usage in Python. Share to everyone for your reference. The specific analysis is as follows: 1. The Assert statement is used to declare that a condition is true. 2. If you are very confident that there is at least one element in the list you are using, and you want to test this and throw an error when it is not t

Friends who have used python assert should often encounter such doubts, such as:(A, b) = (1, ' 1 ')Assert A==b # Error:assertionerrorWhen debugging code, it's hard to see why it's wrong, unless it's written like this:Assert 1== ' 1 ', "fact==expect, [fact]=%s, [expect]=%s"% ([a],[b]) # assertionerror:fact==expect, [fact]=[1], [expect] =[' 1 ']But so every time to

python assert断言是声明布尔值必须为真的判定，如果发生异常就说明表达式为假。可以理解assert断言语句为raise-if-not，用来测试表示式，其返回值为假，就会触发异常。Self.assertequal (a,b,msg=msg) #判断a与. B is consistent, msg similar to remark, can be emptySelf.assertnotequal (a,b,msg=msg) #判断a与b是否不一致Self.asserttrue (A,msg=none) #判断a是否为TrueSelf.assertfalse (B,msg=none) #判断b是否为falseSelf.assertalmostequal (A,b,places=none,msg=none,delta

message to use on failure instead of a list of| Differences.|| Assertsetequal uses ducktyping to support different types of sets, and| is optimized for sets specifically (parameters must support a| Difference method).|| Asserttrue (self, expr, msg=none)| Check the expression is true.|| Asserttupleequal (self, tuple1, Tuple2, Msg=none)| A tuple-specific Equality assertion.|| Args:| Tuple1:the first tuple to compare.| tuple2:the second tuple to compare.| Msg:optional message to use on failure ins

message to use on failure instead of a list of| Differences.|| Assertsetequal uses ducktyping to support different types of sets, and| is optimized for sets specifically (parameters must support a| Difference method).|| Asserttrue (self, expr, msg=none)| Check the expression is true.|| Asserttupleequal (self, tuple1, Tuple2, Msg=none)| A tuple-specific Equality assertion.|| Args:| Tuple1:the first tuple to compare.| tuple2:the second tuple to compare.| Msg:optional message to use on failure ins

execution of a try clause, the remainder of the try clause is ignored. If the type of the exception matches the name after except, then the corresponding except clause is executed. The code after the last try statement is executed. If an exception does not match any of the except, then the exception is passed to the upper try. A try statement may contain multiple except clauses that handle different specific exceptions. Only one branch will be executed at most. Finally will be execute

To deliberately set off an exception, you can use the Raise statement in the following form:Raise RaiseRaise #re-raise the most recent ExceptiThe second form can pass additional data along with the exception, providing details for the processor.Assert If __debug__:If not Raise Assertionerror, Use With/as in 2.6 and later versionswith expression [as varible]:With-blockHere expression returns an object that supports the environment Management protocol. If the AS clause is selected, this object can

Reference documents: http://blog.sina.com.cn/s/blog_59c9412d0100fd55.html1 descriptionJava assertion assert is introduced by jdk1.4.The JVM assertion is turned off by default.Assertions can be locally opened, such as: The parent class prohibits assertions, and subclasses open assertions, so it is generally said that " assertions do not inherit ."　Assertions only apply to complex modal processes.　　Assertions are generally used to judge the execution st

I always thought that assert is just an error function, in fact, it is actually a macro, and the role is not "error."After a certain understanding of its role and use of a certain understanding of the use of assert () is like a "contractual programming", in my understanding, the meaning is that the program under my assumptions, can operate normally good, in fact, the equivalent of an IF statement:if (if est

Assert is used to determine the correctness of the program running and ensure that the program running behavior is consistent with what we understand. The call form is assert (logic expression). If the logic expression is false, abort () is called to terminate the program. View the MSDN help document and get the following explanation for assert: [Cpp]The ANSI