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How can I quickly sum all numbers in a file?
...;
}
-e syntax OK
Just for giggles, I tried this with a file containing 1,000,000 numbers (in the range 0 - 9,999). On my Mac Pro, it returns virtually instantaneously. That's too bad, because I was hoping using mmap would be really fast, but it's just the same time:
use 5.010;
use File::Map qw(ma...
How to iterate for loop in reverse order in swift?
...
With Swift 2.0 it is now: 5.stride(to: 1, by: -1) or 5.stride(through: 1, by: -1)
– Binarian
Sep 21 '15 at 9:23
6
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Tricky Google interview question
... implementation of Dijkstra’s solution.
int main()
{
const int n = 20; // Generate the first n numbers
std::vector<int> v(n);
v[0] = 1;
int i2 = 0; // Index for 2
int i5 = 0; // Index for 5
int x2 = 2 * v[i2]; // Next two candidat...
Obfuscated C Code Contest 2006. Please explain sykes2.c
...>> ";;;====~$::199"[_*2&8|_/64]/(_&2?1:8)%8&1
: 10);
}
Introducing variables to untangle this mess:
main(int i) {
if(i^448)
main(-~i);
if(--i % 64) {
char a = -~7[__TIME__-i/8%8][">'txiZ^(~z?"-48];
char b = a >> ";;;====~$::199"[i...
What's the best practice to round a float to 2 decimals? [duplicate]
...
160
I was working with statistics in Java 2 years ago and I still got the codes of a function that a...
Remove insignificant trailing zeros from a number?
... first place since it was created as a Number, not a String.
var n = 1.245000
var noZeroes = n.toString() // "1.245"
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Converting strings to floats in a DataFrame
...) or pd.to_numeric as described in other
answers.
This is available in 0.11. Forces conversion (or set's to nan)
This will work even when astype will fail; its also series by series
so it won't convert say a complete string column
In [10]: df = DataFrame(dict(A = Series(['1.0','1']), B = Series...
What's the fastest way to merge/join data.frames in R?
...he first example sqldf is 3x slower than data.table and in the second its 200x faster than plyr and 100 times faster than data.table. Below we show the input code, the output timings for the merge and the output timings for the aggregate. Its also worthwhile noting that sqldf is based on a databa...
Split (explode) pandas dataframe string entry to separate rows
... for _, row in a.iterrows()]).reset_index()
Out[55]:
index 0
0 a 1
1 b 1
2 c 1
3 d 2
4 e 2
5 f 2
Then you just have to rename the columns
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What does axis in pandas mean?
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It specifies the axis along which the means are computed. By default axis=0. This is consistent with the numpy.mean usage when axis is specified explicitly (in numpy.mean, axis==None by default, which computes the mean value over the flattened array) , in which axis=0 along the rows (namely, index ...