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What is the best algorithm for overriding GetHashCode?
...hroughout the .NET base class libraries. Implementing it properly is especially important to find items quickly in a collection or when determining equality.
...
Difference between Django's annotate and aggregate methods?
...rage_price': 34.35}
Returns a dictionary containing the average price of all books in the queryset.
Annotation
>>> q = Book.objects.annotate(num_authors=Count('authors'))
>>> q[0].num_authors
2
>>> q[1].num_authors
1
q is the queryset of books, but each book has been...
what's the correct way to send a file from REST web service to client?
...n begin. My REST service is made on Java and I'm using Jersey, I'm sending all the data using the JSON format.
4 Answers
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How do I know if a generator is empty from the start?
..., there is no simple way. There are a whole lot of work-arounds.
There really shouldn't be a simple way, because of what generators are: a way to output a sequence of values without holding the sequence in memory. So there's no backward traversal.
You could write a has_next function or maybe eve...
Get bitcoin historical data [closed]
...ocket in higher resolution over longer time period you could use script log_bitstamp_trades.py below.
The script uses python websocket-client and pusher_client_python libraries, so install them.
#!/usr/bin/python
import pusherclient
import time
import logging
import sys
import datetime
import sig...
Environment variable to control java.io.tmpdir?
...s.
On Windows, OpenJDK's get_temp_directory() function makes a Win32 API call to GetTempPath(); this is how on Windows, Java reflects the value of the TMP environment variable.
On Linux and Solaris, the same get_temp_directory() functions return a static value of /tmp/.
I don't know if the actual...
[精华]VC++对话框程序打印及打印预览的实现 - C/C++ - 清泛网 - 专注C/C++及内核技术
...程序文件菜单中会生成两个菜单项分别是打印（标识符ID_FILE_PRINT）和打印预览(标识符：ID_FILE_PRINT_PREVIEW)，展开程序源代码，可以发现，是CVIEW类提供标准打印和打印预览菜单命令的消息处理函数：
设应用程序视图类为CMyView,展...
Standard deviation of a list
...
The functions are actually called stdev and pstdev, not using std for standard as one would expect. I couldn't edit the post as edits need to modify at least 6 chars...
– mknaf
Jan 6 '17 at 16:00
...
define() vs. const
... a static scalar (number, string or other constant like true, false, null, __FILE__), whereas define() takes any expression. Since PHP 5.6 constant expressions are allowed in const as well:
const BIT_5 = 1 << 5; // Valid since PHP 5.6 and invalid previously
define('BIT_5', 1 << 5); /...
Guaranteed lifetime of temporary in C++?
...or the lifetime of a temporary variable that is created within a function call but not used as a parameter? Here's an example class:
...