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Converting int to bytes in Python 3
...es on an iterable instead of a single integer:
>>> bytes([3])
b'\x03'
The docs state this, as well as the docstring for bytes:
>>> help(bytes)
...
bytes(int) -> bytes object of size given by the parameter initialized with null bytes
...
Unicode character in PHP string
...
Because JSON directly supports the \uxxxx syntax the first thing that comes into my mind is:
$unicodeChar = '\u1000';
echo json_decode('"'.$unicodeChar.'"');
Another option would be to use mb_convert_encoding()
echo mb_convert_encoding('က', 'UTF-8...
Remove columns from dataframe where ALL values are NA
... more memory and time efficient
An approach using Filter
Filter(function(x)!all(is.na(x)), df)
and an approach using data.table (for general time and memory efficiency)
library(data.table)
DT <- as.data.table(df)
DT[,which(unlist(lapply(DT, function(x)!all(is.na(x))))),with=F]
examples usi...
Scatterplot with too many points
...oint plotted on them.
This is easy to do in ggplot2:
df <- data.frame(x = rnorm(5000),y=rnorm(5000))
ggplot(df,aes(x=x,y=y)) + geom_point(alpha = 0.3)
Another convenient way to deal with this is (and probably more appropriate for the number of points you have) is hexagonal binning:
ggplot(...
How to make lists contain only distinct element in Python? [duplicate]
... ''' Modified version of Dave Kirby solution '''
seen = set()
return [x for x in seq if x not in seen and not seen.add(x)]
OK, now how does it work, because it's a little bit tricky here if x not in seen and not seen.add(x):
In [1]: 0 not in [1,2,3] and not print('add')
add
Out[1]: True
Wh...
Convert a matrix to a 1 dimensional array
I have a matrix (32X48).
10 Answers
10
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How to modify a global variable within a function in bash?
... numerical value from 0-255, you can use return to pass the number as the exit status:
mysecondfunc() {
echo "Hello"
return 4
}
var="$(mysecondfunc)"
num_var=$?
echo "$var - num is $num_var"
Gives:
Hello - num is 4
...
How to Correctly Use Lists in R?
...ints out the difference between a list and vector in R:
Why do these two expressions not return the same result?
x = list(1, 2, 3, 4); x2 = list(1:4)
A list can contain any other class as each element. So you can have a list where the first element is a character vector, the second is a data fram...
Remove unwanted parts from strings in a column
...
data['result'] = data['result'].map(lambda x: x.lstrip('+-').rstrip('aAbBcC'))
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Using Pairs or 2-tuples in Java [duplicate]
...but a custom one might be as easy as the following:
public class Tuple<X, Y> {
public final X x;
public final Y y;
public Tuple(X x, Y y) {
this.x = x;
this.y = y;
}
}
Of course, there are some important implications of how to design this class further regarding equa...