[[ has fewer surprises and is generally safer to use. But it is not portable – POSIX doesn’t specify what it does and only some shells support it (beside bash, I heard ksh supports it too). For example, you can do to test whether a file exists. But with [, you have to quote $b, … Read more
I think it’s a historical thing – if a package is introduced as an addition to an existing JRE, it comes in as javax. If it’s first introduced as part of a JRE (like NIO was, I believe) then it comes in as java. Not sure why the new date and time API will end … Read more
You use a self join when a table references data in itself. E.g., an Employee table may have a SupervisorID column that points to the employee that is the boss of the current employee. To query the data and get information for both people in one row, you could self join like this:
Both map and flatMap can be applied to a Stream<T> and they both return a Stream<R>. The difference is that the map operation produces one output value for each input value, whereas the flatMap operation produces an arbitrary number (zero or more) values for each input value. This is reflected in the arguments to each … Read more
The ASCII table is arranged so that the value of the character ‘9’ is nine greater than the value of ‘0’; the value of the character ‘8’ is eight greater than the value of ‘0’; and so on. So you can get the int value of a decimal digit char by subtracting ‘0’.
In simple terms, a stack trace is a list of the method calls that the application was in the middle of when an Exception was thrown. Simple Example With the example given in the question, we can determine exactly where the exception was thrown in the application. Let’s have a look at the stack trace: … Read more
The error TypeError: ‘numpy.ndarray’ object is not callable means that you tried to call a numpy array as a function. Use Instead of
You know what has worked for me really well on windows. My Computer > Properties > Advanced System Settings > Environment Variables > Just add the path as C:\Python27 (or wherever you installed python) OR Then under system variables I create a new Variable called PythonPath. In this variable I have C:\Python27\Lib;C:\Python27\DLLs;C:\Python27\Lib\lib-tk;C:\other-folders-on-the-path This is the … Read more
If you click on the title CSS (SCSS) in CodePen (don’t change the pre-processor with the gear) it will switch to the compiled CSS view.
1) Run below command in powershell with admin mode: 2) run below command in command prompt with admin mode: 3) disabled Hyper-V: Control Panel\Programs\Programs and Features\ 4) VMBox memory made it to: 3155 MB (VMbox->settings->system) VM box Acceleration is deactivated. How do activate this? and fix above error? Restart your system.