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In Python how should I test if a variable is None, True or False
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a = 'foo' if a: print 'its true' a is not actually TRUE, it's just not none
– wesm
Apr 3 '15 at 21:06
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C++ Lock-free Hazard Pointer（冒险指针） - C/C++ - 清泛网 - 专注C/C++及内核技术
C++ Lock-free Hazard Pointer（冒险指针）hazard_pointer1 Safe Reclamation MethodsFolly 的 Hazard Pointer 实现中有一段注释，详细描述了 C++ 里几种主流的安全内存回收方法，列表如下：优点缺点场景Locking易用读高开销
1. Safe Reclamation Methods
Fo...
BLE协议—广播和扫描 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...广播方式的报文有4种，分别为可连接的非定向广播（ADV_IND）、可连接的定向广播（ADV_DIRECT_IND）、可扫描非定向广播（ADV_SCAN_IND）、不可连接的非定向广播（ADV_NONCONN_IND）
4种广播的使用场景各不相同
可连接的非定向广播（A...
Maximum number of records in a MySQL database table
... The poster is not asking about numeric or any other data types. . I really do not understand how this can be flagged as a correct answer. Though I must admit that the question is ambiguous we should distinguish between PK data type and maximum number of rows for a table.
–...
When using a Settings.settings file in .NET, where is the config actually stored?
When using a Settings.settings file in .NET, where is the config actually stored?
I want to delete the saved settings to go back to the default state, but can't find where it's stored... any ideas?
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Identify if a string is a number
...ld use double.TryParse, since we want to know if it represents a number at all.
– John Gietzen
May 21 '09 at 18:31
6
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Get the first element of each tuple in a list in Python [duplicate]
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Use a list comprehension:
res_list = [x[0] for x in rows]
Below is a demonstration:
>>> rows = [(1, 2), (3, 4), (5, 6)]
>>> [x[0] for x in rows]
[1, 3, 5]
>>>
Alternately, you could use unpacking instead of x[0]:
res_li...
Is it true that one should not use NSLog() on production code?
... line number to make it easier to track down log statements.
#define DEBUG_MODE
#ifdef DEBUG_MODE
#define DebugLog( s, ... ) NSLog( @"<%p %@:(%d)> %@", self, [[NSString stringWithUTF8String:__FILE__] lastPathComponent], __LINE__, [NSString stringWithFormat:(s), ##__VA_ARGS__] )
#else
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Why compile Python code?
...ou invoke with python main.py is recompiled every time you run the script. All imported scripts will be compiled and stored on the disk.
Important addition by Ben Blank:
It's worth noting that while running a
compiled script has a faster startup
time (as it doesn't need to be
compiled), i...
How to paste text to end of every line? Sublime 2
...-zA-z0-9!@#$")(*&!+_-] will find the beginning of every line (provided all characters are added for the regex to search for at the beginning each of the lines). Thanks @yohann !
– Tony H.
May 22 '12 at 21:25
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