大约有 43,000 项符合查询结果（耗时：0.0347秒） [XML]
Any reason not to use '+' to concatenate two strings?
...e Python interpreter has to create a new string object for each iteration, and it ends up taking quadratic time. (Recent versions of CPython can apparently optimize this in some cases, but other implementations can't, so programmers are discouraged from relying on this.) ''.join is the right way t...
Algorithm to calculate the number of divisors of a given number
...st of primes you'll need to see how many of those primes act as a divisor (and how often).
Here's some python for the algo Look here and search for "Subject: math - need divisors algorithm". Just count the number of items in the list instead of returning them however.
Here's a Dr. Math that explai...
Programmatically get own phone number in iOS
Is there any way to get own phone number by standard APIs from iPhone SDK?
9 Answers
9...
How to keep a Python script output window open?
...a few options:
Run the program from an already-open terminal. Open a command prompt and type:
python myscript.py
For that to work you need the python executable in your path. Just check on how to edit environment variables on Windows, and add C:\PYTHON26 (or whatever directory you installed pyt...
Linq select objects in list where exists IN (A,B,C)
...ad of array for allowedStatus because HashSet's contains method is fastest and there'll be performance issues with array if it contains more than 1000 items. var allowedStatus = new HashSet<string> { "A", "B", "C" };
– Jay Shah
Nov 9 '18 at 18:14
...
registerForRemoteNotificationTypes: is not supported in iOS 8.0 and later
... team is using both Xcode 5 (which doesn't know about any iOS 8 selectors) and Xcode 6, then you will need to use conditional compiling as follows:
#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 80000
if ([application respondsToSelector:@selector(registerUserNotificationSettings:)]) {
// use registe...
Python String and Integer concatenation [duplicate]
...ed in this answer (backticks) is deprecated in later versions of Python 2, and removed in Python 3. Use the str() function instead.
You can use :
string = 'string'
for i in range(11):
string +=`i`
print string
It will print string012345678910.
To get string0, string1 ..... string10 you can use...
Repeating characters in VIM insert mode
...this sequence works:
Ctrl+o 80i- Esc
Ctrl+o is used to issue normal commands without leaving INSERT mode,
80 the repetition,
i to insert,
- the character you want to insert,
Esc to leave INSERT mode.
Another one without EVER leaving INSERT mode:
Ctrl+o :norm 8ia Return
...
How to install the current version of Go in Ubuntu Precise
...e GVM for managing my Go versions in my Ubuntu box. Pretty simple to use, and if you're familiar with RVM, it's a nobrainer. It allows you to have multiple versions of Go installed in your system and switch between whichever version you want at any point in time.
Install GVM with:
sudo apt-get i...
How can I configure the font size for the tree item in the package explorer in Eclipse?
..., there was no way in Eclipse to change the font used for Package Explorer and other such views. You can only change the font for editor views. This is a policy decision on the part of the Eclipse developers (see, e.g., bugs 49548, 202091). (Grumble.) The font used is the one set by the general look...