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How to change the order of DataFrame columns?
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34 Answers
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Difference between map, applymap and apply methods in Pandas
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Straight from Wes McKinney's Python for Data Analysis book, pg. 132 (I highly recommended this book):
Another frequent operation is applying a function on 1D arrays to each column or row. DataFrame’s apply method does exactly this:
In [116]: frame = DataFrame(np.random.randn(4, 3),...
List comprehension vs map
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$ python -mtimeit -s'xs=range(10)' 'map(hex, xs)'
100000 loops, best of 3: 4.86 usec per loop
$ python -mtimeit -s'xs=range(10)' '[hex(x) for x in xs]'
100000 loops, best of 3: 5.58 usec per loop
An example of how performance comparison gets completely reversed when map needs a lambda:
$ pytho...
How to make a great R reproducible example
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23 Answers
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ros 基本调试 - 更多技术 - 清泛网 - 专注C/C++及内核技术
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2.1.1.1虚拟机
2.1.1.2真实电脑——物理串行线
2.1.1.3基于freebsd的串行终端
2.1.2将调试文字输出到文件
2.1.3将调试文字输出到屏幕
2.1.4修改波特率（数据传输速率）
2.2KDBG
2.3GDB
2.4WINDBG
3.生成更多输出
3.1编译时开启verbosi...
JavaScript function similar to Python range()
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Pass a variable into a partial, rails 3?
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237
Try this:
<% @posts.each do |post| %>
<%= render 'middle', :post => post %>
&...
Return two and more values from a method
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def sumdiff(x, y)
return x+y, x-y
end
#=> nil
sumdiff(3, 4)
#=> [7, -1]
a = sumdiff(3,4)
#=> [7, -1]
a
#=> [7, -1]
a,b=sumdiff(3,4)
#=> [7, -1]
a
#=> 7
b
#=> -1
a,b,c=sumdiff(3,4)
#=> [7, -1]
a
#=> 7
b
#=> -1
c
#=> nil
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How do I choose grid and block dimensions for CUDA kernels?
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3 Answers
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