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Are tuples more efficient than lists in Python?
...much faster than assigning a list.
>>> def a():
... x=[1,2,3,4,5]
... y=x[2]
...
>>> def b():
... x=(1,2,3,4,5)
... y=x[2]
...
>>> import dis
>>> dis.dis(a)
2 0 LOAD_CONST 1 (1)
3 LOAD_CONST 2 ...
pandas three-way joining multiple dataframes on columns
...
497
Assumed imports:
import pandas as pd
John Galt's answer is basically a reduce operation. I...
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...
Real life example, when to use OUTER / CROSS APPLY in SQL
...
4 Answers
4
Active
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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
...
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 ...
Using awk to print all columns from the nth to the last
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24 Answers
24
Active
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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
...
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]:...
Accessing class variables from a list comprehension in the class definition
...
246
Class scope and list, set or dictionary comprehensions, as well as generator expressions do not...