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Why is 1/1/1970 the “epoch time”?
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Early versions of unix measured system time in 1/60 s intervals. This meant that a 32-bit unsigned integer could only represent a span of time less than 829 days. For this reason, the time represented by the number 0 (called the epoch) had to be set in the very recent pas...
Django 1.7 throws django.core.exceptions.AppRegistryNotReady: Models aren't loaded yet
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How does the C code that prints from 1 to 1000 without loops or conditional statements work?
I've found C code that prints from 1 to 1000 without loops or conditionals :
But I don't understand how it works. Can anyone go through the code and explain each line?
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Loop backwards using indices in Python?
I am trying to loop from 100 to 0. How do I do this in Python?
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Printing everything except the first field with awk
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What is the formal difference in Scala between braces and parentheses, and when should they be used?
... if, and only if, the method expects a single parameter. For example:
List(1, 2, 3).reduceLeft{_ + _} // valid, single Function2[Int,Int] parameter
List{1, 2, 3}.reduceLeft(_ + _) // invalid, A* vararg parameter
However, there’s more you need to know to better grasp these rules.
Increased compil...
Waiting until two async blocks are executed before starting another block
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List of lists into numpy array
...nacio Vazquez-Abrams will not work. Instead there are at least 3 options:
1) Make an array of arrays:
x=[[1,2],[1,2,3],[1]]
y=numpy.array([numpy.array(xi) for xi in x])
type(y)
>>><type 'numpy.ndarray'>
type(y[0])
>>><type 'numpy.ndarray'>
2) Make an array of lists:...
Get the latest record from mongodb collection
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This is a rehash of the previous answer but it's more likely to work on different mongodb vers...
MongoDB副本集详解 优于以往的主从模式 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...为mongodb-linux-x86_64-2.6.0
由三台虚拟机搭建，配置为单核,1G内存。实验环境如下:
MongoDB的副本集不同于以往的主从模式。
在集群Master故障的时候，副本集可以自动投票，选举出新的Master，并引导其余的Slave服务器连接新的Master...