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How to rename a single column in a data.frame?
...r.name'
This code pretty much does the following:
names(df) looks into all the names in the df
[names(df) == old.var.name] extracts the variable name you want to check
<- 'new.var.name' assigns the new variable name.
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mfc里面的140种颜色宏 - C/C++ - 清泛网 - 专注C/C++及内核技术
...R_BLACK RGB( 0, 0, 0) // 纯黑
完整.h文件下载：ColorDef.zip
mfc 颜色宏
Checking if all elements in a list are unique
What is the best way (best as in the conventional way) of checking whether all elements in a list are unique?
14 Answers
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How to get Scala List from Java List?
...now built into the language using:
import scala.collection.JavaConversions._
...
lst.toList.foreach{ node => .... }
works. asScala did not work
In 2.12.x use import scala.collection.JavaConverters._
In 2.13.x use import scala.jdk.CollectionConverters._
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What is the best way to implement nested dictionaries?
I have a data structure which essentially amounts to a nested dictionary. Let's say it looks like this:
21 Answers
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Generating random numbers in Objective-C
...te the S-Boxes via
arc4random_addrandom().
There is no need to call arc4random_stir() before using arc4random(), since arc4random() automatically
initializes itself.
EXAMPLES
The following produces a drop-in replacement for the traditional rand() and random() functions using
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Pretty-print an entire Pandas Series / DataFrame
...: # more options can be specified also
print(df)
This will automatically return the options to their previous values.
If you are working on jupyter-notebook, using display(df) instead of print(df) will use jupyter rich display logic (like so).
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usr/bin/ld: cannot find -l
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@ZoOo that shouldn't normally matter, the linker can work with either one
– djf
May 23 '13 at 9:48
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String formatting: % vs. .format vs. string literal
...ated. And Python, not being a lazy language, evaluates expressions before calling functions, so in your log.debug example, the expression "some debug info: %s"%some_infowill first evaluate to, e.g. "some debug info: roflcopters are active", then that string will be passed to log.debug().
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What is the difference between a definition and a declaration?
...// extern can be omitted for function declarations
class foo; // no extern allowed for type declarations
A definition actually instantiates/implements this identifier. It's what the linker needs in order to link references to those entities. These are definitions corresponding to the above declara...