What is a StackOverflowError?

Parameters and local variables are allocated on the stack (with reference types, the object lives on the heap and a variable in the stack references that object on the heap). The stack typically lives at the upper end of your address space and as it is used up it heads towards the bottom of the address space (i.e. towards zero). Your process also … Read more

How to update/upgrade a package using pip?

The way is or in short Using sudo will ask to enter your root password to confirm the action, but although common, is considered unsafe. If you do not have a root password (if you are not the admin) you should probably work with virtualenv. You can also use the user flag to install it on this user only.

Git: How do I force “git pull” to overwrite local files?

⚠ Important: If you have any local changes, they will be lost. With or without –hard option, any local commits that haven’t been pushed will be lost.[*] If you have any files that are not tracked by Git (e.g. uploaded user content), these files will not be affected. First, run a fetch to update all origin/<branch> refs to latest: Backup your … Read more

How to deal with SettingWithCopyWarning in Pandas

The SettingWithCopyWarning was created to flag potentially confusing “chained” assignments, such as the following, which does not always work as expected, particularly when the first selection returns a copy. [see GH5390 and GH5597 for background discussion.] The warning offers a suggestion to rewrite as follows: However, this doesn’t fit your usage, which is equivalent to: While it’s clear that you don’t care … Read more

Emulator: ERROR: x86 emulation currently requires hardware acceleration

As per this response, the complete steps are: 1) Open SDK Manager (In Android Studio, go to Tools > Android > SDK Manager) and Download Intel x86 Emulator Accelerator (HAXM installer) if you haven’t. 2) Now go to your SDK directory C:\users\%USERNAME%\AppData\Local\Android\sdk\extras\intel\Hardware_Accelerated_Execution_Manager\ and run the file named intelhaxm-android.exe. In case you get an error like “Intel virtualization technology (vt,vt-x) … Read more

How do I generate a random int number?

The Random class is used to create random numbers. (Pseudo-random that is of course.). Example: If you are going to create more than one random number, you should keep the Random instance and reuse it. If you create new instances too close in time, they will produce the same series of random numbers as the random generator is seeded from … Read more

How to dynamically allocate arrays in C++

for arrays (which is what you want) or for single elements. But it’s more simple to use vector, or use smartpointers, then you don’t have to worry about memory management. L.data() gives you access to the int[] array buffer and you can L.resize() the vector later. L.get() gives you a pointer to the int[] array.

Which is the difference between Long.valueOf(0) and 0L in Java?

Nothing. will undergo autoboxing. The compiler replaces it with: You can see this if you decompile your class, e.g. using javap. Decompiles to: So how it is better initialize a variable, considering memory consumption and time complexity? Because they are semantically identical, the memory consumption and time complexity is also identical. Instead, focus on what is actually … Read more