global-variables

问题 Consider the following code, why don't I need to pass x to Y? class X: def __init__(self): self.a = 1 self.b = 2 self.c = 3 class Y: def A(self): print(x.a,x.b,x.c) x = X() y = Y() y.A() Thank you to the top answers, they really helped me see what was the problem, namely misunderstanding regarding variable scope. I wish I could choose both as correct answer as they are enlightening in their own way. 回答1: From The Python Tutorial: Although scopes are determined statically, they are used

问题 In C++ Singleton design pattern, obecalp mentioned that: For many larger programs, especially those with dynamic libraries. Any global or static object that's none primitive can lead to segfaults/crashes upon program exit on many platforms due to order of destruction issues upon libraries unloading. This is one of the reasons many coding conventions (including Google's) ban the use of non-trivial static and global objects. Can someone elaborate why this can happen? Maybe an example to explain

问题 In C++ Singleton design pattern, obecalp mentioned that: For many larger programs, especially those with dynamic libraries. Any global or static object that's none primitive can lead to segfaults/crashes upon program exit on many platforms due to order of destruction issues upon libraries unloading. This is one of the reasons many coding conventions (including Google's) ban the use of non-trivial static and global objects. Can someone elaborate why this can happen? Maybe an example to explain

问题 In C++ Singleton design pattern, obecalp mentioned that: For many larger programs, especially those with dynamic libraries. Any global or static object that's none primitive can lead to segfaults/crashes upon program exit on many platforms due to order of destruction issues upon libraries unloading. This is one of the reasons many coding conventions (including Google's) ban the use of non-trivial static and global objects. Can someone elaborate why this can happen? Maybe an example to explain

问题 I have pretty standard Django+Rabbitmq+Celery setup with 1 Celery task and 5 workers. Task uploads the same (I simplify a bit) big file (~100MB) asynchronously to a number of remote PCs. All is working fine at the expense of using lots of memory, since every task/worker load that big file into memory separatelly. What I would like to do is to have some kind of cache, accessible to all tasks, i.e. load the file only once. Django caching based on locmem would be perfect, but like documentation

问题 I have global variables and want to use them within a function. I don't use local variables with the same name within the functions! # Global variables: $Var1 = @{ .. } $Var2 = @( .. ) function testing{ $Var1.keyX = "kjhkjh" $Var2[2] = 6.89768 } I do it and it works, but is it safe or do I have to use the following? $Global:Var1.keyX = "kjhkjh" 回答1: In your function, you are modifying the contents of the hashtable so there is no need to use $global unless your function (or a function caller

问题 Closed . This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed last year . In julia 1.0.0, I get the following for-loop scoping behavior: julia> counts = 0 0 julia> for i in 1:10 counts += 1 end ERROR: UndefVarError: counts not defined I found the solution was to make the counts variable global inside the for loop. julia> for i in 1:10 global counts +

问题 Closed . This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed last year . In julia 1.0.0, I get the following for-loop scoping behavior: julia> counts = 0 0 julia> for i in 1:10 counts += 1 end ERROR: UndefVarError: counts not defined I found the solution was to make the counts variable global inside the for loop. julia> for i in 1:10 global counts +

问题 Even though global Python objects tend to be bad, I more or less forced to use them with module curses . I currently have this: class Window: def __init__(self, title, h, w, y, x): self.window = curses.newwin(h, w, y, x) self.window.box() self.window.hline(2, 1, curses.ACS_HLINE, w-2) self.window.addstr(1, 2, title) self.window.refresh() global top_win top_win = Window('Top window', 6, 32, 3, 6) I am wondering whether it would be possible to get rid of the global line by adding something to

问题 I'm trying to find some help in the ways of "Initializing" A module/Variable inside the module on an event. I need it to load, in order for the following WinForm to use it (apparently) Let me explain... I am using the WinSCP library and gotten plenty of help in the ways of WinSCP by the author himself. But in order to fix my current problem, I need to Initialize a Global Variable. So the Variable is there, its in order, but "Form2" refuses to use it, as it apparently needs to be Started