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Count how many records are in a CSV Python?
...aranteed to be a fixed size, so the only way to count them is to read them all.
– Martijn Pieters♦
Apr 19 '13 at 15:55
1
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What is a memory fence?
...ead/writes occur in the order you expect. For example a 'full fence' means all read/writes before the fence are comitted before those after the fence.
Note memory fences are a hardware concept. In higher level languages we are used to dealing with mutexes and semaphores - these may well be implemen...
How can I default a parameter to Guid.Empty in C#?
...id() instead
public void Problem(Guid optional = new Guid())
{
// when called without parameters this will be true
var guidIsEmpty = optional == Guid.Empty;
}
You can also use default(Guid)
default(Guid) also will work exactly as new Guid().
Because Guid is a value type not reference type, ...
How can you profile a Python script?
...
Python includes a profiler called cProfile. It not only gives the total running time, but also times each function separately, and tells you how many times each function was called, making it easy to determine where you should make optimizations.
You c...
How to use clock() in C++
How do I call clock() in C++ ?
7 Answers
7
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When to favor ng-if vs. ng-show/ng-hide?
...ise the difference:
ng-if will remove elements from DOM. This means that all your handlers or anything else attached to those elements will be lost. For example, if you bound a click handler to one of child elements, when ng-if evaluates to false, that element will be removed from DOM and your cli...
How to get the text node of an element?
...wered Jun 29 '11 at 11:58
James AllardiceJames Allardice
152k2121 gold badges309309 silver badges301301 bronze badges
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Adding :default => true to boolean in existing Rails column
...
change_column is a method of ActiveRecord::Migration, so you can't call it like that in the console.
If you want to add a default value for this column, create a new migration:
rails g migration add_default_value_to_show_attribute
Then in the migration created:
# That's the more generic way t...
Inline SVG in CSS
...possible. I just went to the standard specification and stated it was virtually impossible, which turned out to be a mistake (sort of)
– toniedzwiedz
May 26 '12 at 19:05
18
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C++使用OLE/COM高速读写EXCEL的源码 - C/C++ - 清泛网 - 专注C/C++及内核技术
...m/xianyunhe/archive/2011/09/25/2190485.html
http://blog.sina.com.cn/s/blog_6e51df7f01015cci.html
感谢原作者的无私奉献。
通过VC实现对Excel表格的操作的方法有多种，如：通过ODBC数据库实现，通过解析Excel表格文件，通过OLE/COM的实现。本文主要研...