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How to count the number of set bits in a 32-bit integer?
...33333) + ((i >> 2) & 0x33333333);
return (((i + (i >> 4)) & 0x0F0F0F0F) * 0x01010101) >> 24;
}
For JavaScript: coerce to integer with |0 for performance: change the first line to i = (i|0) - ((i >> 1) & 0x55555555);
This has the best worst-case behaviour of ...
Accessing class variables from a list comprehension in the class definition
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246
Class scope and list, set or dictionary comprehensions, as well as generator expressions do not...
How do I parallelize a simple Python loop?
...est using the multiprocessing module instead:
pool = 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 thre...
pandas three-way joining multiple dataframes on columns
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497
Assumed imports:
import pandas as pd
John Galt's answer is basically a reduce operation. I...
Differences between .NET 4.0 and .NET 4.5 in High level in .NET
Eager to know Differences between .NET 4.0 and .NET 4.5 in High level in .NET and also differences in ASP.NET, C# also in these frameworks
...
Using awk to print all columns from the nth to the last
...
24 Answers
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Active
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How to apply a function to two columns of Pandas dataframe
...s Series object, and then index the Series to get the values needed.
In [49]: df
Out[49]:
0 1
0 1.000000 0.000000
1 -0.494375 0.570994
2 1.000000 0.000000
3 1.876360 -0.229738
4 1.000000 0.000000
In [50]: def f(x):
....: return x[0] + x[1]
....:
In [51]:...
Web scraping with Python [closed]
...
from BeautifulSoup import BeautifulSoup
# or if you're using BeautifulSoup4:
# from bs4 import BeautifulSoup
soup = BeautifulSoup(urllib2.urlopen('http://example.com').read())
for row in soup('table', {'class': 'spad'})[0].tbody('tr'):
tds = row('td')
print tds[0].string, tds[1].string
...
Difference between EXISTS and IN in SQL?
...
answered Aug 24 '08 at 9:37
KeithKeith
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Android 4.3 Bluetooth Low Energy unstable
...ng an application that will use Bluetooth Low Energy (testing on the Nexus 4). After getting started with the official BLE APIs in Android 4.3, I have noticed that after I connect a device for the first time I am rarely able to successfully connect to / communicate with that device or any other devi...