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How to make a flat list out of list of lists?
...e the timeit module in the standard library:
$ python -mtimeit -s'l=[[1,2,3],[4,5,6], [7], [8,9]]*99' '[item for sublist in l for item in sublist]'
10000 loops, best of 3: 143 usec per loop
$ python -mtimeit -s'l=[[1,2,3],[4,5,6], [7], [8,9]]*99' 'sum(l, [])'
1000 loops, best of 3: 969 usec per loo...
Difference between float and decimal data type
...mysql> insert into numbers values (100, 100);
mysql> select @a := (a/3), @b := (b/3), @a * 3, @b * 3 from numbers \G
*************************** 1. row ***************************
@a := (a/3): 33.333333333
@b := (b/3): 33.333333333333
@a + @a + @a: 99.999999999000000000000000000000
@b + @b...
Java 8 NullPointerException in Collectors.toMap
...
13 Answers
13
Active
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Difference between `mod` and `rem` in Haskell
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183
They're not the same when the second argument is negative:
2 `mod` (-3) == -1
2 `rem` (-3) =...
Return two and more values from a method
...
def sumdiff(x, y)
return x+y, x-y
end
#=> nil
sumdiff(3, 4)
#=> [7, -1]
a = sumdiff(3,4)
#=> [7, -1]
a
#=> [7, -1]
a,b=sumdiff(3,4)
#=> [7, -1]
a
#=> 7
b
#=> -1
a,b,c=sumdiff(3,4)
#=> [7, -1]
a
#=> 7
b
#=> -1
c
#=> nil
...
Iterating over dictionaries using 'for' loops
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13 Answers
13
Active
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How do I check which version of NumPy I'm using?
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392
import numpy
numpy.version.version
...
What is non-blocking or asynchronous I/O in Node.js?
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322
Synchronous vs Asynchronous
Synchronous execution usually refers to code executing in sequenc...
Initializing a member array in constructor initializer
...assignments in the body. This is what boost::array does.
Does the C++03 standard say anything special about initializing aggregates (including arrays) in ctor initializers? Or the invalidness of the above code is a corollary of some other rules?
A mem-initializer uses direct initialization. ...
FIND_IN_SET() vs IN()
... to the first non-digit (a comma in your case).
Thus,
companyID IN ('1,2,3') ≡ companyID IN (CAST('1,2,3' AS INT)) ≡ companyID IN (1)
In PostgreSQL, you could cast the string into array (or store it as an array in the first place):
SELECT name
FROM orders
JOIN company
ON company...