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Split column at delimiter in data frame [duplicate]
...me.
I added a "x|y" line to avoid ambiguities:
df <- data.frame(ID=11:13, FOO=c('a|b','b|c','x|y'))
foo <- data.frame(do.call('rbind', strsplit(as.character(df$FOO),'|',fixed=TRUE)))
Or, if you want to replace the columns in the existing data.frame:
within(df, FOO<-data.frame(do.call('r...
Difference between Repository and Service Layer?
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330
Repository Layer gives you additional level of abstraction over data access. Instead of writin...
Is it worth using Python's re.compile?
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TriptychTriptych
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Equivalent C++ to Python generator pattern
...rator_tag,
std::pair<unsigned, unsigned>
>
{
// C++03
typedef void (PairSequence::*BoolLike)();
void non_comparable();
public:
// C++11 (explicit aliases)
using iterator_category = std::input_iterator_tag;
using value_type = std::pair<unsigned, unsigned>;
usi...
Is there a performance difference between i++ and ++i in C++?
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432
[Executive Summary: Use ++i if you don't have a specific reason to use i++.]
For C++, the answ...
Matrix Transpose in Python
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310
Python 2:
>>> theArray = [['a','b','c'],['d','e','f'],['g','h','i']]
>>> zi...
When should you use constexpr capability in C++11?
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303
Suppose it does something a little more complicated.
constexpr int MeaningOfLife ( int a, int ...
Why do I get a segmentation fault when writing to a “char *s” initialized with a string literal, but
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See the C FAQ, Question 1.32
Q: What is the difference between these initializations?
char a[] = "string literal";
char *p = "string literal";
My program crashes if I try to assign a new value to p[i].
A: A string literal (the formal t...
Create a temporary table in a SELECT statement without a separate CREATE TABLE
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edited Feb 4 '16 at 10:30
maxhb
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answered May ...