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Do you (really) write exception safe code? [closed]
Exception handling (EH) seems to be the current standard, and by searching the web, I can not find any novel ideas or methods that try to improve or replace it (well, some variations exist, but nothing novel).
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How to group dataframe rows into list in pandas groupby?
...b, dtype: object
In [3]: df1 = df.groupby('a')['b'].apply(list).reset_index(name='new')
df1
Out[3]:
a new
0 A [1, 2]
1 B [5, 5, 4]
2 C [6]
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How do you remove duplicates from a list whilst preserving order?
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Remove characters from C# string
How might I remove characters from a string? For example: "My name @is ,Wan.;'; Wan" .
21 Answers
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Converting string to numeric [duplicate]
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I suspect you are having a problem with factors. For example,
> x = factor(4:8)
> x
[1] 4 5 6 7 8
Levels: 4 5 6 7 8
> as.numeric(x)
[1] 1 2 3 4 5
> as.numeric(as.character(x))
[1] 4 5 6 7 8
Some comments:
You mention that your vector contains the characters "Do...
Complex numbers usage in python [closed]
...tting deeper into Python data types. I can't understand how to use a complex number. Please give me examples of usage of complex numbers in Python.
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OS X10.9 环境下部署 QT5.3.1 常见的编译问题 - 更多技术 - 清泛网 - 专注C/C++及内核技术
OS X10.9 环境下部署 QT5.3.1 常见的编译问题出于本身对UNIX系统的好奇，以及身边一群对 Swift 语言各种推崇的苹果教徒的影响，这几天折腾起 MAC OS X来，体验下这个被无数开发者...
出于本身对UNIX系统的好奇，以及身边一群对 Swift ...
What size should TabBar images be?
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30x30 is points, which means 30px @1x, 60px @2x, not somewhere in-between. Also, it's not a great idea to embed the title of the tab into the image—you're going to have pretty poor accessibility and localization results like ...
How can I add reflection to a C++ application?
...e it easier and cleaner to write it in the preprocessor we will use typed expression. A typed expression is just an expression that puts the type in parenthesis. So instead of writing int x you will write (int) x. Here are some handy macros to help with typed expressions:
#define REM(...) __VA_ARGS...
How to get row from R data.frame
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x[r,]
where r is the row you're interested in. Try this, for example:
#Add your data
x <- structure(list(A = c(5, 3.5, 3.25, 4.25, 1.5 ),
B = c(4.25, 4, 4, 4.5, 4.5 ),
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