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Shortcuts in Objective-C to concatenate NSStrings
...or whatever to the return value of this function.
Or, to make a shortcut, convert the NSString into a C++ string and use the '+' there.
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How does RegexOptions.Compiled work?
...the regular expression engine to compile the regular expression expression into IL using lightweight code generation (LCG). This compilation happens during the construction of the object and heavily slows it down. In turn, matches using the regular expression are faster.
If you do not specify this ...
When do I use a dot, arrow, or double colon to refer to members of a class in C++?
...ect of a class that overloads operator-> (common such types are smart pointers and iterators), then the meaning is whatever the class designer implemented. To conclude: With a->b, if a is a pointer, b will be a member of the object the pointer a refers to. If, however, a is an object of a clas...
How to group dataframe rows into list in pandas groupby?
..., x, y]
C [6] [z]
To group-listify a single column only, convert the groupby to a SeriesGroupBy object, then call SeriesGroupBy.agg. Use,
df.groupby('a').agg({'b': list}) # 4.42 ms
df.groupby('a')['b'].agg(list) # 2.76 ms - faster
a
A [1, 2]
B [5, 5, 4]
C [...
Is it better to use std::memcpy() or std::copy() in terms to performance?
... of its information. When you call std::copy, the function keeps the types intact. memcpy operates on void *, which discards almost all useful information. For instance, if I pass in an array of std::uint64_t, the compiler or library implementer may be able to take advantage of 64-bit alignment with...
How can I remove non-ASCII characters but leave periods and spaces using Python?
...fferent codec, is by using encode() or decode(). In your case, you want to convert to ASCII and ignore all symbols that are not supported. For example, the Swedish letter å is not an ASCII character:
>>>s = u'Good bye in Swedish is Hej d\xe5'
>>>s = s.encode('ascii',error...
Can't install RMagick 2.13.1. Can't find MagickWand.h.
...irst of all, do you have imagemagick installed? If you're not sure, run
$ convert --version
If you do, you probably either installed it with fink or macports (maybe homebrew?). What is happening is that rvm can't find the imagemagick directory.
After reading
https://superuser.com/questions/36143...
How to “pretty” format JSON output in Ruby on Rails
...g to do with this patch. Also, Time.parse returns the same result when you convert the string back to time for both formats. It'd only be a minor inconvenience when searching logs for time stamps, but if you're grepping anyway adding a few \s+ isn't really a big deal.
– con--
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“Cloning” row or column vectors
...is useful to "clone" a row or column vector to a matrix. By cloning I mean converting a row vector such as
9 Answers
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What permission do I need to access Internet from an Android application?
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Add the INTERNET permission to your manifest file.
You have to add this line:
<uses-permission android:name="android.permission.INTERNET" />
outside the application tag in your AndroidManifest.xml
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