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get list of pandas dataframe columns based on data type
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320
If you want a list of columns of a certain type, you can use groupby:
>>> df = pd.Da...
Difference between a “coroutine” and a “thread”?
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answered Dec 20 '09 at 3:10
Alex MartelliAlex Martelli
724k148148 gold badges11261126 silver badges13241324 bronze badges
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Where can I learn how to write C code to speed up slow R functions? [closed]
...yfold increases with C++ (on what is of course a contrived example).
Edit 3: There is complexity in that you may run into C++ errors that are, to put it mildly, hard to grok. But to just use Rcpp rather than to extend it, you should hardly ever need it. And while this cost is undeniable, it is fa...
'printf' vs. 'cout' in C++
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360
I'm surprised that everyone in this question claims that std::cout is way better than printf, ...
On Duplicate Key Update same as insert
...ernatively, you can use:
INSERT INTO table (id,a,b,c,d,e,f,g)
VALUES (1,2,3,4,5,6,7,8)
ON DUPLICATE KEY
UPDATE a=a, b=b, c=c, d=d, e=e, f=f, g=g;
To get the id from LAST_INSERT_ID; you need to specify the backend app you're using for the same.
For LuaSQL, a conn:getlastautoid() fetches the ...
How to determine if one array contains all elements of another array
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313
a = [5, 1, 6, 14, 2, 8]
b = [2, 6, 15]
a - b
=> [5, 1, 14, 8]
b - a
=> [15]
(b - a).e...
Convert char to int in C and C++
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lucidbrot
3,11022 gold badges2424 silver badges4848 bronze badges
answered Feb 17 '11 at 14:16
Foo BahFoo Bah
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Why do objects of the same class have access to each other's private data?
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edited Aug 3 '11 at 3:31
answered Aug 3 '11 at 3:26
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Python group by
...Do it in 2 steps. First, create a dictionary.
>>> input = [('11013331', 'KAT'), ('9085267', 'NOT'), ('5238761', 'ETH'), ('5349618', 'ETH'), ('11788544', 'NOT'), ('962142', 'ETH'), ('7795297', 'ETH'), ('7341464', 'ETH'), ('9843236', 'KAT'), ('5594916', 'ETH'), ('1550003', 'ETH')]
>>&g...