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Can dplyr package be used for conditional mutating?
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220
Use ifelse
df %>%
mutate(g = ifelse(a == 2 | a == 5 | a == 7 | (a == 1 & b == 4), 2,
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Python creating a dictionary of lists
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286
You can use defaultdict:
>>> from collections import defaultdict
>>> d = de...
Ruby 2.0.0p0 IRB warning: “DL is deprecated, please use Fiddle”
...ions of Ruby, removed all of my gems
(including Rails), and installed Ruby 2.0. In other words, a totally clean re-install. Upon starting IRB, I received this message:
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Operation on every pair of element in a list
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233
Check out product() in the itertools module. It does exactly what you describe.
import itert...
How to split a column into two columns?
... row
0 00000 UNITED STATES
1 01000 ALABAMA
2 01001 Autauga County, AL
3 01003 Baldwin County, AL
4 01005 Barbour County, AL
df = pd.DataFrame(df.row.str.split(' ',1).tolist(),
columns = ['flips','row'])
flips ...
How to check if variable is string with python 2 and 3 compatibility
...str) in python-3.x but I need to check if something is a string in python-2.x as well. Will isinstance(x, str) work as expected in python-2.x? Or will I need to check the version and use isinstance(x, basestr) ?
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Unicode与UTF-8互转(C语言实现) - C/C++ - 清泛网 - 专注C/C++及内核技术
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位(bit)有0和1两种状态, 因此八个二进制位就可以组合出 256种状态, 这被称为一个字
节(byte). 也就是说, 一个字节一共可以用来表示256种不同的状态, 每一个状态对应一
个符号, 就是256个符号, 从 0000000到11111111.
上个世纪60年代...
C++/COM VARIANT实现二维数组 - C/C++ - 清泛网 - 专注C/C++及内核技术
...，包括设置数组元素的类型、数据的维数，大小等。
（2）对SAFEARRAY数组赋值，既可通过SafeArrayPutElement函数逐个元素进行负责，也可通过指针来获得SAFEARRAY的数据地址，然后对指针指向的值进行赋值操作。其中，如果SAFEARRAY中...
WinDBG用法详解 PDF - 文档下载 - 清泛网 - 专注C/C++及内核技术
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