大约有 40,000 项符合查询结果(耗时:0.0570秒) [XML]

https://stackoverflow.com/ques... 

How do I load a file from resource folder?

...e examples of how that class is used: src\main\java\com\company\test\YourCallingClass.java src\main\java\com\opensymphony\xwork2\util\ClassLoaderUtil.java src\main\resources\test.csv // java.net.URL URL url = ClassLoaderUtil.getResource("test.csv", YourCallingClass.class); Path path = Paths.get(ur...
https://stackoverflow.com/ques... 

How to overcome TypeError: unhashable type: 'list'

...used to compare dictionary keys during a dictionary lookup quickly. Internally, hash() method calls __hash__() method of an object which are set by default for any object. Converting a nested list to a set >>> a = [1,2,3,4,[5,6,7],8,9] >>> set(a) Traceback (most recent call last...
https://stackoverflow.com/ques... 

How do you create different variable names while in a loop? [duplicate]

...can do this is with exec(). For example: for k in range(5): exec(f'cat_{k} = k*2') >>> print(cat_0) 0 >>> print(cat_1) 2 >>> print(cat_2) 4 >>> print(cat_3) 6 >>> print(cat_4) 8 Here I am taking advantage of the handy f string formatting in Pytho...
https://stackoverflow.com/ques... 

How can I store my users' passwords safely?

...tials'; } (In case you are still using legacy 5.3.7 or newer you can install ircmaxell/password_compat to have access to the build-in functions) Improving upon salted hashes: add pepper If you want extra security, the security folks now (2017) recommend adding a 'pepper' to the (automatically)...
https://stackoverflow.com/ques... 

What are the differences between Perl, Python, AWK and sed? [closed]

...is designed to apply the actions from a script to each line (or, more generally, to specified ranges of lines) of the input file or files. Its language is based on ed, the Unix editor, and although it has conditionals and so on, it is hard to work with for complex tasks. You can work minor miracles ...
https://stackoverflow.com/ques... 

Why doesn't GCC optimize a*a*a*a*a*a to (a*a*a)*(a*a*a)?

...scientific application. One thing I noticed is that GCC will optimize the call pow(a,2) by compiling it into a*a , but the call pow(a,6) is not optimized and will actually call the library function pow , which greatly slows down the performance. (In contrast, Intel C++ Compiler , executable ...
https://stackoverflow.com/ques... 

When should you use constexpr capability in C++11?

... "function that always returns 5" is breaking or diluting the meaning of "calling a function". There must be a reason, or a need for this capability or it wouldn't be in C++11. Why is it there? ...
https://stackoverflow.com/ques... 

C# pattern to prevent an event handler hooked twice [duplicate]

...ution and the best one (considering performance) is: private EventHandler _foo; public event EventHandler Foo { add { _foo -= value; _foo += value; } remove { _foo -= value; } } No Linq using required. No need to check for null before cancelling a subscrip...
https://stackoverflow.com/ques... 

What are 'closures' in .NET?

...thod and the variable j [CompilerGenerated] private sealed class <>c__DisplayClass2 { public <>c__DisplayClass2(); public void <fillFunc>b__0() { Console.Write("{0} ", this.j); } public int j; } for the function: static void fillFunc(int count) { ...
https://stackoverflow.com/ques... 

Improve INSERT-per-second performance of SQLite

...more memory will be used for your database. If you have indices, consider calling CREATE INDEX after doing all your inserts. This is significantly faster than creating the index and then doing your inserts. You have to be quite careful if you have concurrent access to SQLite, as the whole database i...