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How do I parallelize a simple Python loop?
...ool = multiprocessing.Pool(4)
out1, out2, out3 = zip(*pool.map(calc_stuff, range(0, 10 * offset, offset)))
Note that this won't work in the interactive interpreter.
To avoid the usual FUD around the GIL: There wouldn't be any advantage to using threads for this example anyway. You want to use pr...
Statistics: combinations in Python
...ion
def nCk(n,k):
return int( reduce(mul, (Fraction(n-i, i+1) for i in range(k)), 1) )
Test - printing Pascal's triangle:
>>> for n in range(17):
... print ' '.join('%5d'%nCk(n,k) for k in range(n+1)).center(100)
...
1 ...
How do I decode HTML entities in Swift?
...p;' and copy the characters preceding it to `result`:
while let ampRange = self[position...].range(of: "&") {
result.append(contentsOf: self[position ..< ampRange.lowerBound])
position = ampRange.lowerBound
// Find the next ';' and copy everything ...
Putting text in top left corner of matplotlib plot
...atter(xd,xd,xd, marker='o', s=20, c="goldenrod", alpha=0.9)
line1 = Line2D(range(10), range(10), marker='o', color="goldenrod")
line2 = Line2D(range(10), range(10), marker='o',color="firebrick")
line3 = Line2D(range(10), range(10), marker='o',color="lightgreen")
line4 = Line2D(range(10), range(10), ...
Value of i for (i == -i && i != 0) to return true in Java
...amming language uses two's-complement representation for integers, and the range of two's-complement values is not symmetric, so negation of the maximum negative int or long results in that same maximum negative number."
– chesterbr
Jul 26 '13 at 4:11
...
List comprehension vs. lambda + filter
...
It is strange how much beauty varies for different people. I find the list comprehension much clearer than filter+lambda, but use whichever you find easier.
There are two things that may slow down your use of filter.
The first is t...
How to use timeit module
...import random
random.seed('slartibartfast')
s = [random.random() for i in range(1000)]
timsort = list.sort
'''
>>> print min(timeit.Timer('a=s[:]; timsort(a)', setup=setup).repeat(7, 1000))
0.334147930145
Note that the series of statements makes a fresh copy of the unsorted data on ever...
How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly
...es and use that to index into your frame:
>>> df = pd.DataFrame([range(3), [0, np.NaN, 0], [0, 0, np.NaN], range(3), range(3)])
>>> df.isnull()
0 1 2
0 False False False
1 False True False
2 False False True
3 False False False
4 False False False...
Finding out whether a string is numeric or not
... = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
if ([newString rangeOfCharacterFromSet:notDigits].location == NSNotFound)
{
// newString consists only of the digits 0 through 9
}
See +[NSCharacterSet decimalDigitCharacterSet] and -[NSString rangeOfCharacterFromSet:].
...
Why does the month argument range from 0 to 11 in JavaScript's Date constructor?
...ng but the day of the month is 0 based, see here for a full list including ranges :)
It's actually the 1 based days that are the oddballs here...oddly enough. Why was this was done? I don't know...but probably happened the same meeting they got plastered and decided semicolons were optional.
...