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How is “int* ptr = int()” value initialization not illegal?
...
110
int() is a constant expression with a value of 0, so it's a valid way of producing a null pointe...
How to get the first column of a pandas DataFrame as a Series?
...ataFrame({'x' : [1, 2, 3, 4], 'y' : [4, 5, 6, 7]})
>>> df
x y
0 1 4
1 2 5
2 3 6
3 4 7
>>> s = df.ix[:,0]
>>> type(s)
<class 'pandas.core.series.Series'>
>>>
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UPDATE
If...
Installing specific package versions with pip
...s here: http://pypi.python.org/pypi/MySQL-python/1.2.2
The download link 404s and the fallback URL links are re-directing infinitely due to sourceforge.net's recent upgrade and PyPI's stale URL.
So to properly install the driver, you can follow these steps:
pip uninstall MySQL_python
pip install ...
How to automatically generate N “distinct” colors?
...tness or saturation, you can distribute the hues like so:
// assumes hue [0, 360), saturation [0, 100), lightness [0, 100)
for(i = 0; i < 360; i += 360 / num_colors) {
HSLColor c;
c.hue = i;
c.saturation = 90 + randf() * 10;
c.lightness = 50 + randf() * 10;
addColor(c);
}
...
The modulo operation on negative numbers in Python
...nually fix it up by adding 7:
int result = (2 - N) % 7;
return result < 0 ? result + 7 : result;
(See http://en.wikipedia.org/wiki/Modulo_operator for how the sign of result is determined for different languages.)
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...
Standard deviation of a list
...
Since Python 3.4 / PEP450 there is a statistics module in the standard library, which has a method stdev for calculating the standard deviation of iterables like yours:
>>> A_rank = [0.8, 0.4, 1.2, 3.7, 2.6, 5.8]
>>> import statis...
How to nicely format floating numbers to String without unnecessary decimal 0?
...
407
If the idea is to print integers stored as doubles as if they are integers, and otherwise print...
plot a circle with pyplot
...
205
You need to add it to an axes. A Circle is a subclass of an Artist, and an axes has an add_arti...
How do I round to the nearest 0.5?
...
208
Multiply your rating by 2, then round using Math.Round(rating, MidpointRounding.AwayFromZero), ...
Append value to empty vector in R?
...et.seed(21)
values <- sample(letters, 1e4, TRUE)
vector <- character(0)
# slow
system.time( for (i in 1:length(values)) vector[i] <- values[i] )
# user system elapsed
# 0.340 0.000 0.343
vector <- character(length(values))
# fast(er)
system.time( for (i in 1:length(values)) vec...